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OpenCloudOS-Kernel/arch/powerpc/kvm/book3s_hv_nested.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright IBM Corporation, 2018
* Authors Suraj Jitindar Singh <sjitindarsingh@gmail.com>
* Paul Mackerras <paulus@ozlabs.org>
*
* Description: KVM functions specific to running nested KVM-HV guests
* on Book3S processors (specifically POWER9 and later).
*/
#include <linux/kernel.h>
#include <linux/kvm_host.h>
#include <linux/llist.h>
#include <linux/pgtable.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/mmu.h>
#include <asm/pgalloc.h>
#include <asm/pte-walk.h>
#include <asm/reg.h>
#include <asm/plpar_wrappers.h>
static struct patb_entry *pseries_partition_tb;
static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp);
static void kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot *free);
void kvmhv_save_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr)
{
struct kvmppc_vcore *vc = vcpu->arch.vcore;
hr->pcr = vc->pcr | PCR_MASK;
hr->dpdes = vc->dpdes;
hr->hfscr = vcpu->arch.hfscr;
hr->tb_offset = vc->tb_offset;
hr->dawr0 = vcpu->arch.dawr0;
hr->dawrx0 = vcpu->arch.dawrx0;
hr->ciabr = vcpu->arch.ciabr;
hr->purr = vcpu->arch.purr;
hr->spurr = vcpu->arch.spurr;
hr->ic = vcpu->arch.ic;
hr->vtb = vc->vtb;
hr->srr0 = vcpu->arch.shregs.srr0;
hr->srr1 = vcpu->arch.shregs.srr1;
hr->sprg[0] = vcpu->arch.shregs.sprg0;
hr->sprg[1] = vcpu->arch.shregs.sprg1;
hr->sprg[2] = vcpu->arch.shregs.sprg2;
hr->sprg[3] = vcpu->arch.shregs.sprg3;
hr->pidr = vcpu->arch.pid;
hr->cfar = vcpu->arch.cfar;
hr->ppr = vcpu->arch.ppr;
hr->dawr1 = vcpu->arch.dawr1;
hr->dawrx1 = vcpu->arch.dawrx1;
}
/* Use noinline_for_stack due to https://bugs.llvm.org/show_bug.cgi?id=49610 */
static noinline_for_stack void byteswap_pt_regs(struct pt_regs *regs)
{
unsigned long *addr = (unsigned long *) regs;
for (; addr < ((unsigned long *) (regs + 1)); addr++)
*addr = swab64(*addr);
}
static void byteswap_hv_regs(struct hv_guest_state *hr)
{
hr->version = swab64(hr->version);
hr->lpid = swab32(hr->lpid);
hr->vcpu_token = swab32(hr->vcpu_token);
hr->lpcr = swab64(hr->lpcr);
hr->pcr = swab64(hr->pcr) | PCR_MASK;
hr->amor = swab64(hr->amor);
hr->dpdes = swab64(hr->dpdes);
hr->hfscr = swab64(hr->hfscr);
hr->tb_offset = swab64(hr->tb_offset);
hr->dawr0 = swab64(hr->dawr0);
hr->dawrx0 = swab64(hr->dawrx0);
hr->ciabr = swab64(hr->ciabr);
hr->hdec_expiry = swab64(hr->hdec_expiry);
hr->purr = swab64(hr->purr);
hr->spurr = swab64(hr->spurr);
hr->ic = swab64(hr->ic);
hr->vtb = swab64(hr->vtb);
hr->hdar = swab64(hr->hdar);
hr->hdsisr = swab64(hr->hdsisr);
hr->heir = swab64(hr->heir);
hr->asdr = swab64(hr->asdr);
hr->srr0 = swab64(hr->srr0);
hr->srr1 = swab64(hr->srr1);
hr->sprg[0] = swab64(hr->sprg[0]);
hr->sprg[1] = swab64(hr->sprg[1]);
hr->sprg[2] = swab64(hr->sprg[2]);
hr->sprg[3] = swab64(hr->sprg[3]);
hr->pidr = swab64(hr->pidr);
hr->cfar = swab64(hr->cfar);
hr->ppr = swab64(hr->ppr);
hr->dawr1 = swab64(hr->dawr1);
hr->dawrx1 = swab64(hr->dawrx1);
}
static void save_hv_return_state(struct kvm_vcpu *vcpu,
struct hv_guest_state *hr)
{
struct kvmppc_vcore *vc = vcpu->arch.vcore;
hr->dpdes = vc->dpdes;
hr->purr = vcpu->arch.purr;
hr->spurr = vcpu->arch.spurr;
hr->ic = vcpu->arch.ic;
hr->vtb = vc->vtb;
hr->srr0 = vcpu->arch.shregs.srr0;
hr->srr1 = vcpu->arch.shregs.srr1;
hr->sprg[0] = vcpu->arch.shregs.sprg0;
hr->sprg[1] = vcpu->arch.shregs.sprg1;
hr->sprg[2] = vcpu->arch.shregs.sprg2;
hr->sprg[3] = vcpu->arch.shregs.sprg3;
hr->pidr = vcpu->arch.pid;
hr->cfar = vcpu->arch.cfar;
hr->ppr = vcpu->arch.ppr;
switch (vcpu->arch.trap) {
case BOOK3S_INTERRUPT_H_DATA_STORAGE:
hr->hdar = vcpu->arch.fault_dar;
hr->hdsisr = vcpu->arch.fault_dsisr;
hr->asdr = vcpu->arch.fault_gpa;
break;
case BOOK3S_INTERRUPT_H_INST_STORAGE:
hr->asdr = vcpu->arch.fault_gpa;
break;
case BOOK3S_INTERRUPT_H_FAC_UNAVAIL:
hr->hfscr = ((~HFSCR_INTR_CAUSE & hr->hfscr) |
(HFSCR_INTR_CAUSE & vcpu->arch.hfscr));
break;
case BOOK3S_INTERRUPT_H_EMUL_ASSIST:
hr->heir = vcpu->arch.emul_inst;
break;
}
}
static void restore_hv_regs(struct kvm_vcpu *vcpu, const struct hv_guest_state *hr)
{
struct kvmppc_vcore *vc = vcpu->arch.vcore;
vc->pcr = hr->pcr | PCR_MASK;
vc->dpdes = hr->dpdes;
vcpu->arch.hfscr = hr->hfscr;
vcpu->arch.dawr0 = hr->dawr0;
vcpu->arch.dawrx0 = hr->dawrx0;
vcpu->arch.ciabr = hr->ciabr;
vcpu->arch.purr = hr->purr;
vcpu->arch.spurr = hr->spurr;
vcpu->arch.ic = hr->ic;
vc->vtb = hr->vtb;
vcpu->arch.shregs.srr0 = hr->srr0;
vcpu->arch.shregs.srr1 = hr->srr1;
vcpu->arch.shregs.sprg0 = hr->sprg[0];
vcpu->arch.shregs.sprg1 = hr->sprg[1];
vcpu->arch.shregs.sprg2 = hr->sprg[2];
vcpu->arch.shregs.sprg3 = hr->sprg[3];
vcpu->arch.pid = hr->pidr;
vcpu->arch.cfar = hr->cfar;
vcpu->arch.ppr = hr->ppr;
vcpu->arch.dawr1 = hr->dawr1;
vcpu->arch.dawrx1 = hr->dawrx1;
}
void kvmhv_restore_hv_return_state(struct kvm_vcpu *vcpu,
struct hv_guest_state *hr)
{
struct kvmppc_vcore *vc = vcpu->arch.vcore;
vc->dpdes = hr->dpdes;
vcpu->arch.hfscr = hr->hfscr;
vcpu->arch.purr = hr->purr;
vcpu->arch.spurr = hr->spurr;
vcpu->arch.ic = hr->ic;
vc->vtb = hr->vtb;
vcpu->arch.fault_dar = hr->hdar;
vcpu->arch.fault_dsisr = hr->hdsisr;
vcpu->arch.fault_gpa = hr->asdr;
vcpu->arch.emul_inst = hr->heir;
vcpu->arch.shregs.srr0 = hr->srr0;
vcpu->arch.shregs.srr1 = hr->srr1;
vcpu->arch.shregs.sprg0 = hr->sprg[0];
vcpu->arch.shregs.sprg1 = hr->sprg[1];
vcpu->arch.shregs.sprg2 = hr->sprg[2];
vcpu->arch.shregs.sprg3 = hr->sprg[3];
vcpu->arch.pid = hr->pidr;
vcpu->arch.cfar = hr->cfar;
vcpu->arch.ppr = hr->ppr;
}
static void kvmhv_nested_mmio_needed(struct kvm_vcpu *vcpu, u64 regs_ptr)
{
/* No need to reflect the page fault to L1, we've handled it */
vcpu->arch.trap = 0;
/*
* Since the L2 gprs have already been written back into L1 memory when
* we complete the mmio, store the L1 memory location of the L2 gpr
* being loaded into by the mmio so that the loaded value can be
* written there in kvmppc_complete_mmio_load()
*/
if (((vcpu->arch.io_gpr & KVM_MMIO_REG_EXT_MASK) == KVM_MMIO_REG_GPR)
&& (vcpu->mmio_is_write == 0)) {
vcpu->arch.nested_io_gpr = (gpa_t) regs_ptr +
offsetof(struct pt_regs,
gpr[vcpu->arch.io_gpr]);
vcpu->arch.io_gpr = KVM_MMIO_REG_NESTED_GPR;
}
}
static int kvmhv_read_guest_state_and_regs(struct kvm_vcpu *vcpu,
struct hv_guest_state *l2_hv,
struct pt_regs *l2_regs,
u64 hv_ptr, u64 regs_ptr)
{
int size;
if (kvm_vcpu_read_guest(vcpu, hv_ptr, &l2_hv->version,
sizeof(l2_hv->version)))
return -1;
if (kvmppc_need_byteswap(vcpu))
l2_hv->version = swab64(l2_hv->version);
size = hv_guest_state_size(l2_hv->version);
if (size < 0)
return -1;
return kvm_vcpu_read_guest(vcpu, hv_ptr, l2_hv, size) ||
kvm_vcpu_read_guest(vcpu, regs_ptr, l2_regs,
sizeof(struct pt_regs));
}
static int kvmhv_write_guest_state_and_regs(struct kvm_vcpu *vcpu,
struct hv_guest_state *l2_hv,
struct pt_regs *l2_regs,
u64 hv_ptr, u64 regs_ptr)
{
int size;
size = hv_guest_state_size(l2_hv->version);
if (size < 0)
return -1;
return kvm_vcpu_write_guest(vcpu, hv_ptr, l2_hv, size) ||
kvm_vcpu_write_guest(vcpu, regs_ptr, l2_regs,
sizeof(struct pt_regs));
}
static void load_l2_hv_regs(struct kvm_vcpu *vcpu,
const struct hv_guest_state *l2_hv,
const struct hv_guest_state *l1_hv, u64 *lpcr)
{
struct kvmppc_vcore *vc = vcpu->arch.vcore;
u64 mask;
restore_hv_regs(vcpu, l2_hv);
/*
* Don't let L1 change LPCR bits for the L2 except these:
*/
mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_AIL | LPCR_LD |
LPCR_LPES | LPCR_MER;
/*
* Additional filtering is required depending on hardware
* and configuration.
*/
*lpcr = kvmppc_filter_lpcr_hv(vcpu->kvm,
(vc->lpcr & ~mask) | (*lpcr & mask));
/*
* Don't let L1 enable features for L2 which we don't allow for L1,
* but preserve the interrupt cause field.
*/
vcpu->arch.hfscr = l2_hv->hfscr & (HFSCR_INTR_CAUSE | vcpu->arch.hfscr_permitted);
/* Don't let data address watchpoint match in hypervisor state */
vcpu->arch.dawrx0 = l2_hv->dawrx0 & ~DAWRX_HYP;
vcpu->arch.dawrx1 = l2_hv->dawrx1 & ~DAWRX_HYP;
/* Don't let completed instruction address breakpt match in HV state */
if ((l2_hv->ciabr & CIABR_PRIV) == CIABR_PRIV_HYPER)
vcpu->arch.ciabr = l2_hv->ciabr & ~CIABR_PRIV;
}
long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
{
long int err, r;
struct kvm_nested_guest *l2;
struct pt_regs l2_regs, saved_l1_regs;
struct hv_guest_state l2_hv = {0}, saved_l1_hv;
struct kvmppc_vcore *vc = vcpu->arch.vcore;
u64 hv_ptr, regs_ptr;
u64 hdec_exp, lpcr;
s64 delta_purr, delta_spurr, delta_ic, delta_vtb;
if (vcpu->kvm->arch.l1_ptcr == 0)
return H_NOT_AVAILABLE;
if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr))
return H_BAD_MODE;
/* copy parameters in */
hv_ptr = kvmppc_get_gpr(vcpu, 4);
regs_ptr = kvmppc_get_gpr(vcpu, 5);
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
err = kvmhv_read_guest_state_and_regs(vcpu, &l2_hv, &l2_regs,
hv_ptr, regs_ptr);
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
if (err)
return H_PARAMETER;
if (kvmppc_need_byteswap(vcpu))
byteswap_hv_regs(&l2_hv);
if (l2_hv.version > HV_GUEST_STATE_VERSION)
return H_P2;
if (kvmppc_need_byteswap(vcpu))
byteswap_pt_regs(&l2_regs);
if (l2_hv.vcpu_token >= NR_CPUS)
return H_PARAMETER;
/*
* L1 must have set up a suspended state to enter the L2 in a
* transactional state, and only in that case. These have to be
* filtered out here to prevent causing a TM Bad Thing in the
* host HRFID. We could synthesize a TM Bad Thing back to the L1
* here but there doesn't seem like much point.
*/
if (MSR_TM_SUSPENDED(vcpu->arch.shregs.msr)) {
if (!MSR_TM_ACTIVE(l2_regs.msr))
return H_BAD_MODE;
} else {
if (l2_regs.msr & MSR_TS_MASK)
return H_BAD_MODE;
if (WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_TS_MASK))
return H_BAD_MODE;
}
/* translate lpid */
l2 = kvmhv_get_nested(vcpu->kvm, l2_hv.lpid, true);
if (!l2)
return H_PARAMETER;
if (!l2->l1_gr_to_hr) {
mutex_lock(&l2->tlb_lock);
kvmhv_update_ptbl_cache(l2);
mutex_unlock(&l2->tlb_lock);
}
/* save l1 values of things */
vcpu->arch.regs.msr = vcpu->arch.shregs.msr;
saved_l1_regs = vcpu->arch.regs;
kvmhv_save_hv_regs(vcpu, &saved_l1_hv);
/* convert TB values/offsets to host (L0) values */
hdec_exp = l2_hv.hdec_expiry - vc->tb_offset;
vc->tb_offset += l2_hv.tb_offset;
/* set L1 state to L2 state */
vcpu->arch.nested = l2;
vcpu->arch.nested_vcpu_id = l2_hv.vcpu_token;
l2->hfscr = l2_hv.hfscr;
vcpu->arch.regs = l2_regs;
/* Guest must always run with ME enabled, HV disabled. */
vcpu->arch.shregs.msr = (vcpu->arch.regs.msr | MSR_ME) & ~MSR_HV;
lpcr = l2_hv.lpcr;
load_l2_hv_regs(vcpu, &l2_hv, &saved_l1_hv, &lpcr);
vcpu->arch.ret = RESUME_GUEST;
vcpu->arch.trap = 0;
do {
if (mftb() >= hdec_exp) {
vcpu->arch.trap = BOOK3S_INTERRUPT_HV_DECREMENTER;
r = RESUME_HOST;
break;
}
r = kvmhv_run_single_vcpu(vcpu, hdec_exp, lpcr);
} while (is_kvmppc_resume_guest(r));
/* save L2 state for return */
l2_regs = vcpu->arch.regs;
l2_regs.msr = vcpu->arch.shregs.msr;
delta_purr = vcpu->arch.purr - l2_hv.purr;
delta_spurr = vcpu->arch.spurr - l2_hv.spurr;
delta_ic = vcpu->arch.ic - l2_hv.ic;
delta_vtb = vc->vtb - l2_hv.vtb;
save_hv_return_state(vcpu, &l2_hv);
/* restore L1 state */
vcpu->arch.nested = NULL;
vcpu->arch.regs = saved_l1_regs;
vcpu->arch.shregs.msr = saved_l1_regs.msr & ~MSR_TS_MASK;
/* set L1 MSR TS field according to L2 transaction state */
if (l2_regs.msr & MSR_TS_MASK)
vcpu->arch.shregs.msr |= MSR_TS_S;
vc->tb_offset = saved_l1_hv.tb_offset;
restore_hv_regs(vcpu, &saved_l1_hv);
vcpu->arch.purr += delta_purr;
vcpu->arch.spurr += delta_spurr;
vcpu->arch.ic += delta_ic;
vc->vtb += delta_vtb;
kvmhv_put_nested(l2);
/* copy l2_hv_state and regs back to guest */
if (kvmppc_need_byteswap(vcpu)) {
byteswap_hv_regs(&l2_hv);
byteswap_pt_regs(&l2_regs);
}
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
err = kvmhv_write_guest_state_and_regs(vcpu, &l2_hv, &l2_regs,
hv_ptr, regs_ptr);
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
if (err)
return H_AUTHORITY;
if (r == -EINTR)
return H_INTERRUPT;
if (vcpu->mmio_needed) {
kvmhv_nested_mmio_needed(vcpu, regs_ptr);
return H_TOO_HARD;
}
return vcpu->arch.trap;
}
long kvmhv_nested_init(void)
{
long int ptb_order;
unsigned long ptcr;
long rc;
if (!kvmhv_on_pseries())
return 0;
if (!radix_enabled())
return -ENODEV;
/* find log base 2 of KVMPPC_NR_LPIDS, rounding up */
ptb_order = __ilog2(KVMPPC_NR_LPIDS - 1) + 1;
if (ptb_order < 8)
ptb_order = 8;
pseries_partition_tb = kmalloc(sizeof(struct patb_entry) << ptb_order,
GFP_KERNEL);
if (!pseries_partition_tb) {
pr_err("kvm-hv: failed to allocated nested partition table\n");
return -ENOMEM;
}
ptcr = __pa(pseries_partition_tb) | (ptb_order - 8);
rc = plpar_hcall_norets(H_SET_PARTITION_TABLE, ptcr);
if (rc != H_SUCCESS) {
pr_err("kvm-hv: Parent hypervisor does not support nesting (rc=%ld)\n",
rc);
kfree(pseries_partition_tb);
pseries_partition_tb = NULL;
return -ENODEV;
}
return 0;
}
void kvmhv_nested_exit(void)
{
/*
* N.B. the kvmhv_on_pseries() test is there because it enables
* the compiler to remove the call to plpar_hcall_norets()
* when CONFIG_PPC_PSERIES=n.
*/
if (kvmhv_on_pseries() && pseries_partition_tb) {
plpar_hcall_norets(H_SET_PARTITION_TABLE, 0);
kfree(pseries_partition_tb);
pseries_partition_tb = NULL;
}
}
static void kvmhv_flush_lpid(unsigned int lpid)
{
long rc;
if (!kvmhv_on_pseries()) {
radix__flush_all_lpid(lpid);
return;
}
if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE))
rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(2, 0, 1),
lpid, TLBIEL_INVAL_SET_LPID);
else
rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU,
H_RPTI_TYPE_NESTED |
H_RPTI_TYPE_TLB | H_RPTI_TYPE_PWC |
H_RPTI_TYPE_PAT,
H_RPTI_PAGE_ALL, 0, -1UL);
if (rc)
pr_err("KVM: TLB LPID invalidation hcall failed, rc=%ld\n", rc);
}
void kvmhv_set_ptbl_entry(unsigned int lpid, u64 dw0, u64 dw1)
{
if (!kvmhv_on_pseries()) {
mmu_partition_table_set_entry(lpid, dw0, dw1, true);
return;
}
pseries_partition_tb[lpid].patb0 = cpu_to_be64(dw0);
pseries_partition_tb[lpid].patb1 = cpu_to_be64(dw1);
/* L0 will do the necessary barriers */
kvmhv_flush_lpid(lpid);
}
static void kvmhv_set_nested_ptbl(struct kvm_nested_guest *gp)
{
unsigned long dw0;
dw0 = PATB_HR | radix__get_tree_size() |
__pa(gp->shadow_pgtable) | RADIX_PGD_INDEX_SIZE;
kvmhv_set_ptbl_entry(gp->shadow_lpid, dw0, gp->process_table);
}
void kvmhv_vm_nested_init(struct kvm *kvm)
{
kvm->arch.max_nested_lpid = -1;
}
/*
* Handle the H_SET_PARTITION_TABLE hcall.
* r4 = guest real address of partition table + log_2(size) - 12
* (formatted as for the PTCR).
*/
long kvmhv_set_partition_table(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = vcpu->kvm;
unsigned long ptcr = kvmppc_get_gpr(vcpu, 4);
int srcu_idx;
long ret = H_SUCCESS;
srcu_idx = srcu_read_lock(&kvm->srcu);
/*
* Limit the partition table to 4096 entries (because that's what
* hardware supports), and check the base address.
*/
if ((ptcr & PRTS_MASK) > 12 - 8 ||
!kvm_is_visible_gfn(vcpu->kvm, (ptcr & PRTB_MASK) >> PAGE_SHIFT))
ret = H_PARAMETER;
srcu_read_unlock(&kvm->srcu, srcu_idx);
if (ret == H_SUCCESS)
kvm->arch.l1_ptcr = ptcr;
return ret;
}
/*
* Handle the H_COPY_TOFROM_GUEST hcall.
* r4 = L1 lpid of nested guest
* r5 = pid
* r6 = eaddr to access
* r7 = to buffer (L1 gpa)
* r8 = from buffer (L1 gpa)
* r9 = n bytes to copy
*/
long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu)
{
struct kvm_nested_guest *gp;
int l1_lpid = kvmppc_get_gpr(vcpu, 4);
int pid = kvmppc_get_gpr(vcpu, 5);
gva_t eaddr = kvmppc_get_gpr(vcpu, 6);
gpa_t gp_to = (gpa_t) kvmppc_get_gpr(vcpu, 7);
gpa_t gp_from = (gpa_t) kvmppc_get_gpr(vcpu, 8);
void *buf;
unsigned long n = kvmppc_get_gpr(vcpu, 9);
bool is_load = !!gp_to;
long rc;
if (gp_to && gp_from) /* One must be NULL to determine the direction */
return H_PARAMETER;
if (eaddr & (0xFFFUL << 52))
return H_PARAMETER;
buf = kzalloc(n, GFP_KERNEL);
if (!buf)
return H_NO_MEM;
gp = kvmhv_get_nested(vcpu->kvm, l1_lpid, false);
if (!gp) {
rc = H_PARAMETER;
goto out_free;
}
mutex_lock(&gp->tlb_lock);
if (is_load) {
/* Load from the nested guest into our buffer */
rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid,
eaddr, buf, NULL, n);
if (rc)
goto not_found;
/* Write what was loaded into our buffer back to the L1 guest */
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
rc = kvm_vcpu_write_guest(vcpu, gp_to, buf, n);
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
if (rc)
goto not_found;
} else {
/* Load the data to be stored from the L1 guest into our buf */
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
rc = kvm_vcpu_read_guest(vcpu, gp_from, buf, n);
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
if (rc)
goto not_found;
/* Store from our buffer into the nested guest */
rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid,
eaddr, NULL, buf, n);
if (rc)
goto not_found;
}
out_unlock:
mutex_unlock(&gp->tlb_lock);
kvmhv_put_nested(gp);
out_free:
kfree(buf);
return rc;
not_found:
rc = H_NOT_FOUND;
goto out_unlock;
}
/*
* Reload the partition table entry for a guest.
* Caller must hold gp->tlb_lock.
*/
static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp)
{
int ret;
struct patb_entry ptbl_entry;
unsigned long ptbl_addr;
struct kvm *kvm = gp->l1_host;
ret = -EFAULT;
ptbl_addr = (kvm->arch.l1_ptcr & PRTB_MASK) + (gp->l1_lpid << 4);
if (gp->l1_lpid < (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 8))) {
int srcu_idx = srcu_read_lock(&kvm->srcu);
ret = kvm_read_guest(kvm, ptbl_addr,
&ptbl_entry, sizeof(ptbl_entry));
srcu_read_unlock(&kvm->srcu, srcu_idx);
}
if (ret) {
gp->l1_gr_to_hr = 0;
gp->process_table = 0;
} else {
gp->l1_gr_to_hr = be64_to_cpu(ptbl_entry.patb0);
gp->process_table = be64_to_cpu(ptbl_entry.patb1);
}
kvmhv_set_nested_ptbl(gp);
}
static struct kvm_nested_guest *kvmhv_alloc_nested(struct kvm *kvm, unsigned int lpid)
{
struct kvm_nested_guest *gp;
long shadow_lpid;
gp = kzalloc(sizeof(*gp), GFP_KERNEL);
if (!gp)
return NULL;
gp->l1_host = kvm;
gp->l1_lpid = lpid;
mutex_init(&gp->tlb_lock);
gp->shadow_pgtable = pgd_alloc(kvm->mm);
if (!gp->shadow_pgtable)
goto out_free;
shadow_lpid = kvmppc_alloc_lpid();
if (shadow_lpid < 0)
goto out_free2;
gp->shadow_lpid = shadow_lpid;
gp->radix = 1;
memset(gp->prev_cpu, -1, sizeof(gp->prev_cpu));
return gp;
out_free2:
pgd_free(kvm->mm, gp->shadow_pgtable);
out_free:
kfree(gp);
return NULL;
}
/*
* Free up any resources allocated for a nested guest.
*/
static void kvmhv_release_nested(struct kvm_nested_guest *gp)
{
struct kvm *kvm = gp->l1_host;
if (gp->shadow_pgtable) {
/*
* No vcpu is using this struct and no call to
* kvmhv_get_nested can find this struct,
* so we don't need to hold kvm->mmu_lock.
*/
kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable,
gp->shadow_lpid);
pgd_free(kvm->mm, gp->shadow_pgtable);
}
kvmhv_set_ptbl_entry(gp->shadow_lpid, 0, 0);
kvmppc_free_lpid(gp->shadow_lpid);
kfree(gp);
}
static void kvmhv_remove_nested(struct kvm_nested_guest *gp)
{
struct kvm *kvm = gp->l1_host;
int lpid = gp->l1_lpid;
long ref;
spin_lock(&kvm->mmu_lock);
if (gp == kvm->arch.nested_guests[lpid]) {
kvm->arch.nested_guests[lpid] = NULL;
if (lpid == kvm->arch.max_nested_lpid) {
while (--lpid >= 0 && !kvm->arch.nested_guests[lpid])
;
kvm->arch.max_nested_lpid = lpid;
}
--gp->refcnt;
}
ref = gp->refcnt;
spin_unlock(&kvm->mmu_lock);
if (ref == 0)
kvmhv_release_nested(gp);
}
/*
* Free up all nested resources allocated for this guest.
* This is called with no vcpus of the guest running, when
* switching the guest to HPT mode or when destroying the
* guest.
*/
void kvmhv_release_all_nested(struct kvm *kvm)
{
int i;
struct kvm_nested_guest *gp;
struct kvm_nested_guest *freelist = NULL;
struct kvm_memory_slot *memslot;
int srcu_idx;
spin_lock(&kvm->mmu_lock);
for (i = 0; i <= kvm->arch.max_nested_lpid; i++) {
gp = kvm->arch.nested_guests[i];
if (!gp)
continue;
kvm->arch.nested_guests[i] = NULL;
if (--gp->refcnt == 0) {
gp->next = freelist;
freelist = gp;
}
}
kvm->arch.max_nested_lpid = -1;
spin_unlock(&kvm->mmu_lock);
while ((gp = freelist) != NULL) {
freelist = gp->next;
kvmhv_release_nested(gp);
}
srcu_idx = srcu_read_lock(&kvm->srcu);
kvm_for_each_memslot(memslot, kvm_memslots(kvm))
kvmhv_free_memslot_nest_rmap(memslot);
srcu_read_unlock(&kvm->srcu, srcu_idx);
}
/* caller must hold gp->tlb_lock */
static void kvmhv_flush_nested(struct kvm_nested_guest *gp)
{
struct kvm *kvm = gp->l1_host;
spin_lock(&kvm->mmu_lock);
kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable, gp->shadow_lpid);
spin_unlock(&kvm->mmu_lock);
kvmhv_flush_lpid(gp->shadow_lpid);
kvmhv_update_ptbl_cache(gp);
if (gp->l1_gr_to_hr == 0)
kvmhv_remove_nested(gp);
}
struct kvm_nested_guest *kvmhv_get_nested(struct kvm *kvm, int l1_lpid,
bool create)
{
struct kvm_nested_guest *gp, *newgp;
if (l1_lpid >= KVM_MAX_NESTED_GUESTS ||
l1_lpid >= (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 12 - 4)))
return NULL;
spin_lock(&kvm->mmu_lock);
gp = kvm->arch.nested_guests[l1_lpid];
if (gp)
++gp->refcnt;
spin_unlock(&kvm->mmu_lock);
if (gp || !create)
return gp;
newgp = kvmhv_alloc_nested(kvm, l1_lpid);
if (!newgp)
return NULL;
spin_lock(&kvm->mmu_lock);
if (kvm->arch.nested_guests[l1_lpid]) {
/* someone else beat us to it */
gp = kvm->arch.nested_guests[l1_lpid];
} else {
kvm->arch.nested_guests[l1_lpid] = newgp;
++newgp->refcnt;
gp = newgp;
newgp = NULL;
if (l1_lpid > kvm->arch.max_nested_lpid)
kvm->arch.max_nested_lpid = l1_lpid;
}
++gp->refcnt;
spin_unlock(&kvm->mmu_lock);
if (newgp)
kvmhv_release_nested(newgp);
return gp;
}
void kvmhv_put_nested(struct kvm_nested_guest *gp)
{
struct kvm *kvm = gp->l1_host;
long ref;
spin_lock(&kvm->mmu_lock);
ref = --gp->refcnt;
spin_unlock(&kvm->mmu_lock);
if (ref == 0)
kvmhv_release_nested(gp);
}
static struct kvm_nested_guest *kvmhv_find_nested(struct kvm *kvm, int lpid)
{
if (lpid > kvm->arch.max_nested_lpid)
return NULL;
return kvm->arch.nested_guests[lpid];
}
pte_t *find_kvm_nested_guest_pte(struct kvm *kvm, unsigned long lpid,
unsigned long ea, unsigned *hshift)
{
struct kvm_nested_guest *gp;
pte_t *pte;
gp = kvmhv_find_nested(kvm, lpid);
if (!gp)
return NULL;
VM_WARN(!spin_is_locked(&kvm->mmu_lock),
"%s called with kvm mmu_lock not held \n", __func__);
pte = __find_linux_pte(gp->shadow_pgtable, ea, NULL, hshift);
return pte;
}
static inline bool kvmhv_n_rmap_is_equal(u64 rmap_1, u64 rmap_2)
{
return !((rmap_1 ^ rmap_2) & (RMAP_NESTED_LPID_MASK |
RMAP_NESTED_GPA_MASK));
}
void kvmhv_insert_nest_rmap(struct kvm *kvm, unsigned long *rmapp,
struct rmap_nested **n_rmap)
{
struct llist_node *entry = ((struct llist_head *) rmapp)->first;
struct rmap_nested *cursor;
u64 rmap, new_rmap = (*n_rmap)->rmap;
/* Are there any existing entries? */
if (!(*rmapp)) {
/* No -> use the rmap as a single entry */
*rmapp = new_rmap | RMAP_NESTED_IS_SINGLE_ENTRY;
return;
}
/* Do any entries match what we're trying to insert? */
for_each_nest_rmap_safe(cursor, entry, &rmap) {
if (kvmhv_n_rmap_is_equal(rmap, new_rmap))
return;
}
/* Do we need to create a list or just add the new entry? */
rmap = *rmapp;
if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */
*rmapp = 0UL;
llist_add(&((*n_rmap)->list), (struct llist_head *) rmapp);
if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */
(*n_rmap)->list.next = (struct llist_node *) rmap;
/* Set NULL so not freed by caller */
*n_rmap = NULL;
}
static void kvmhv_update_nest_rmap_rc(struct kvm *kvm, u64 n_rmap,
unsigned long clr, unsigned long set,
unsigned long hpa, unsigned long mask)
{
unsigned long gpa;
unsigned int shift, lpid;
pte_t *ptep;
gpa = n_rmap & RMAP_NESTED_GPA_MASK;
lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT;
/* Find the pte */
ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
/*
* If the pte is present and the pfn is still the same, update the pte.
* If the pfn has changed then this is a stale rmap entry, the nested
* gpa actually points somewhere else now, and there is nothing to do.
* XXX A future optimisation would be to remove the rmap entry here.
*/
if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa)) {
__radix_pte_update(ptep, clr, set);
kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
}
}
/*
* For a given list of rmap entries, update the rc bits in all ptes in shadow
* page tables for nested guests which are referenced by the rmap list.
*/
void kvmhv_update_nest_rmap_rc_list(struct kvm *kvm, unsigned long *rmapp,
unsigned long clr, unsigned long set,
unsigned long hpa, unsigned long nbytes)
{
struct llist_node *entry = ((struct llist_head *) rmapp)->first;
struct rmap_nested *cursor;
unsigned long rmap, mask;
if ((clr | set) & ~(_PAGE_DIRTY | _PAGE_ACCESSED))
return;
mask = PTE_RPN_MASK & ~(nbytes - 1);
hpa &= mask;
for_each_nest_rmap_safe(cursor, entry, &rmap)
kvmhv_update_nest_rmap_rc(kvm, rmap, clr, set, hpa, mask);
}
static void kvmhv_remove_nest_rmap(struct kvm *kvm, u64 n_rmap,
unsigned long hpa, unsigned long mask)
{
struct kvm_nested_guest *gp;
unsigned long gpa;
unsigned int shift, lpid;
pte_t *ptep;
gpa = n_rmap & RMAP_NESTED_GPA_MASK;
lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT;
gp = kvmhv_find_nested(kvm, lpid);
if (!gp)
return;
/* Find and invalidate the pte */
ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
/* Don't spuriously invalidate ptes if the pfn has changed */
if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa))
kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid);
}
static void kvmhv_remove_nest_rmap_list(struct kvm *kvm, unsigned long *rmapp,
unsigned long hpa, unsigned long mask)
{
struct llist_node *entry = llist_del_all((struct llist_head *) rmapp);
struct rmap_nested *cursor;
unsigned long rmap;
for_each_nest_rmap_safe(cursor, entry, &rmap) {
kvmhv_remove_nest_rmap(kvm, rmap, hpa, mask);
kfree(cursor);
}
}
/* called with kvm->mmu_lock held */
void kvmhv_remove_nest_rmap_range(struct kvm *kvm,
const struct kvm_memory_slot *memslot,
unsigned long gpa, unsigned long hpa,
unsigned long nbytes)
{
unsigned long gfn, end_gfn;
unsigned long addr_mask;
if (!memslot)
return;
gfn = (gpa >> PAGE_SHIFT) - memslot->base_gfn;
end_gfn = gfn + (nbytes >> PAGE_SHIFT);
addr_mask = PTE_RPN_MASK & ~(nbytes - 1);
hpa &= addr_mask;
for (; gfn < end_gfn; gfn++) {
unsigned long *rmap = &memslot->arch.rmap[gfn];
kvmhv_remove_nest_rmap_list(kvm, rmap, hpa, addr_mask);
}
}
static void kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot *free)
{
unsigned long page;
for (page = 0; page < free->npages; page++) {
unsigned long rmap, *rmapp = &free->arch.rmap[page];
struct rmap_nested *cursor;
struct llist_node *entry;
entry = llist_del_all((struct llist_head *) rmapp);
for_each_nest_rmap_safe(cursor, entry, &rmap)
kfree(cursor);
}
}
static bool kvmhv_invalidate_shadow_pte(struct kvm_vcpu *vcpu,
struct kvm_nested_guest *gp,
long gpa, int *shift_ret)
{
struct kvm *kvm = vcpu->kvm;
bool ret = false;
pte_t *ptep;
int shift;
spin_lock(&kvm->mmu_lock);
ptep = find_kvm_nested_guest_pte(kvm, gp->l1_lpid, gpa, &shift);
if (!shift)
shift = PAGE_SHIFT;
if (ptep && pte_present(*ptep)) {
kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid);
ret = true;
}
spin_unlock(&kvm->mmu_lock);
if (shift_ret)
*shift_ret = shift;
return ret;
}
static inline int get_ric(unsigned int instr)
{
return (instr >> 18) & 0x3;
}
static inline int get_prs(unsigned int instr)
{
return (instr >> 17) & 0x1;
}
static inline int get_r(unsigned int instr)
{
return (instr >> 16) & 0x1;
}
static inline int get_lpid(unsigned long r_val)
{
return r_val & 0xffffffff;
}
static inline int get_is(unsigned long r_val)
{
return (r_val >> 10) & 0x3;
}
static inline int get_ap(unsigned long r_val)
{
return (r_val >> 5) & 0x7;
}
static inline long get_epn(unsigned long r_val)
{
return r_val >> 12;
}
static int kvmhv_emulate_tlbie_tlb_addr(struct kvm_vcpu *vcpu, int lpid,
int ap, long epn)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_nested_guest *gp;
long npages;
int shift, shadow_shift;
unsigned long addr;
shift = ap_to_shift(ap);
addr = epn << 12;
if (shift < 0)
/* Invalid ap encoding */
return -EINVAL;
addr &= ~((1UL << shift) - 1);
npages = 1UL << (shift - PAGE_SHIFT);
gp = kvmhv_get_nested(kvm, lpid, false);
if (!gp) /* No such guest -> nothing to do */
return 0;
mutex_lock(&gp->tlb_lock);
/* There may be more than one host page backing this single guest pte */
do {
kvmhv_invalidate_shadow_pte(vcpu, gp, addr, &shadow_shift);
npages -= 1UL << (shadow_shift - PAGE_SHIFT);
addr += 1UL << shadow_shift;
} while (npages > 0);
mutex_unlock(&gp->tlb_lock);
kvmhv_put_nested(gp);
return 0;
}
static void kvmhv_emulate_tlbie_lpid(struct kvm_vcpu *vcpu,
struct kvm_nested_guest *gp, int ric)
{
struct kvm *kvm = vcpu->kvm;
mutex_lock(&gp->tlb_lock);
switch (ric) {
case 0:
/* Invalidate TLB */
spin_lock(&kvm->mmu_lock);
kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable,
gp->shadow_lpid);
kvmhv_flush_lpid(gp->shadow_lpid);
spin_unlock(&kvm->mmu_lock);
break;
case 1:
/*
* Invalidate PWC
* We don't cache this -> nothing to do
*/
break;
case 2:
/* Invalidate TLB, PWC and caching of partition table entries */
kvmhv_flush_nested(gp);
break;
default:
break;
}
mutex_unlock(&gp->tlb_lock);
}
static void kvmhv_emulate_tlbie_all_lpid(struct kvm_vcpu *vcpu, int ric)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_nested_guest *gp;
int i;
spin_lock(&kvm->mmu_lock);
for (i = 0; i <= kvm->arch.max_nested_lpid; i++) {
gp = kvm->arch.nested_guests[i];
if (gp) {
spin_unlock(&kvm->mmu_lock);
kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
spin_lock(&kvm->mmu_lock);
}
}
spin_unlock(&kvm->mmu_lock);
}
static int kvmhv_emulate_priv_tlbie(struct kvm_vcpu *vcpu, unsigned int instr,
unsigned long rsval, unsigned long rbval)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_nested_guest *gp;
int r, ric, prs, is, ap;
int lpid;
long epn;
int ret = 0;
ric = get_ric(instr);
prs = get_prs(instr);
r = get_r(instr);
lpid = get_lpid(rsval);
is = get_is(rbval);
/*
* These cases are invalid and are not handled:
* r != 1 -> Only radix supported
* prs == 1 -> Not HV privileged
* ric == 3 -> No cluster bombs for radix
* is == 1 -> Partition scoped translations not associated with pid
* (!is) && (ric == 1 || ric == 2) -> Not supported by ISA
*/
if ((!r) || (prs) || (ric == 3) || (is == 1) ||
((!is) && (ric == 1 || ric == 2)))
return -EINVAL;
switch (is) {
case 0:
/*
* We know ric == 0
* Invalidate TLB for a given target address
*/
epn = get_epn(rbval);
ap = get_ap(rbval);
ret = kvmhv_emulate_tlbie_tlb_addr(vcpu, lpid, ap, epn);
break;
case 2:
/* Invalidate matching LPID */
gp = kvmhv_get_nested(kvm, lpid, false);
if (gp) {
kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
kvmhv_put_nested(gp);
}
break;
case 3:
/* Invalidate ALL LPIDs */
kvmhv_emulate_tlbie_all_lpid(vcpu, ric);
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
/*
* This handles the H_TLB_INVALIDATE hcall.
* Parameters are (r4) tlbie instruction code, (r5) rS contents,
* (r6) rB contents.
*/
long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu)
{
int ret;
ret = kvmhv_emulate_priv_tlbie(vcpu, kvmppc_get_gpr(vcpu, 4),
kvmppc_get_gpr(vcpu, 5), kvmppc_get_gpr(vcpu, 6));
if (ret)
return H_PARAMETER;
return H_SUCCESS;
}
static long do_tlb_invalidate_nested_all(struct kvm_vcpu *vcpu,
unsigned long lpid, unsigned long ric)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_nested_guest *gp;
gp = kvmhv_get_nested(kvm, lpid, false);
if (gp) {
kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
kvmhv_put_nested(gp);
}
return H_SUCCESS;
}
/*
* Number of pages above which we invalidate the entire LPID rather than
* flush individual pages.
*/
static unsigned long tlb_range_flush_page_ceiling __read_mostly = 33;
static long do_tlb_invalidate_nested_tlb(struct kvm_vcpu *vcpu,
unsigned long lpid,
unsigned long pg_sizes,
unsigned long start,
unsigned long end)
{
int ret = H_P4;
unsigned long addr, nr_pages;
struct mmu_psize_def *def;
unsigned long psize, ap, page_size;
bool flush_lpid;
for (psize = 0; psize < MMU_PAGE_COUNT; psize++) {
def = &mmu_psize_defs[psize];
if (!(pg_sizes & def->h_rpt_pgsize))
continue;
nr_pages = (end - start) >> def->shift;
flush_lpid = nr_pages > tlb_range_flush_page_ceiling;
if (flush_lpid)
return do_tlb_invalidate_nested_all(vcpu, lpid,
RIC_FLUSH_TLB);
addr = start;
ap = mmu_get_ap(psize);
page_size = 1UL << def->shift;
do {
ret = kvmhv_emulate_tlbie_tlb_addr(vcpu, lpid, ap,
get_epn(addr));
if (ret)
return H_P4;
addr += page_size;
} while (addr < end);
}
return ret;
}
/*
* Performs partition-scoped invalidations for nested guests
* as part of H_RPT_INVALIDATE hcall.
*/
long do_h_rpt_invalidate_pat(struct kvm_vcpu *vcpu, unsigned long lpid,
unsigned long type, unsigned long pg_sizes,
unsigned long start, unsigned long end)
{
/*
* If L2 lpid isn't valid, we need to return H_PARAMETER.
*
* However, nested KVM issues a L2 lpid flush call when creating
* partition table entries for L2. This happens even before the
* corresponding shadow lpid is created in HV which happens in
* H_ENTER_NESTED call. Since we can't differentiate this case from
* the invalid case, we ignore such flush requests and return success.
*/
if (!kvmhv_find_nested(vcpu->kvm, lpid))
return H_SUCCESS;
/*
* A flush all request can be handled by a full lpid flush only.
*/
if ((type & H_RPTI_TYPE_NESTED_ALL) == H_RPTI_TYPE_NESTED_ALL)
return do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_ALL);
/*
* We don't need to handle a PWC flush like process table here,
* because intermediate partition scoped table in nested guest doesn't
* really have PWC. Only level we have PWC is in L0 and for nested
* invalidate at L0 we always do kvm_flush_lpid() which does
* radix__flush_all_lpid(). For range invalidate at any level, we
* are not removing the higher level page tables and hence there is
* no PWC invalidate needed.
*
* if (type & H_RPTI_TYPE_PWC) {
* ret = do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_PWC);
* if (ret)
* return H_P4;
* }
*/
if (start == 0 && end == -1)
return do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_TLB);
if (type & H_RPTI_TYPE_TLB)
return do_tlb_invalidate_nested_tlb(vcpu, lpid, pg_sizes,
start, end);
return H_SUCCESS;
}
/* Used to convert a nested guest real address to a L1 guest real address */
static int kvmhv_translate_addr_nested(struct kvm_vcpu *vcpu,
struct kvm_nested_guest *gp,
unsigned long n_gpa, unsigned long dsisr,
struct kvmppc_pte *gpte_p)
{
u64 fault_addr, flags = dsisr & DSISR_ISSTORE;
int ret;
ret = kvmppc_mmu_walk_radix_tree(vcpu, n_gpa, gpte_p, gp->l1_gr_to_hr,
&fault_addr);
if (ret) {
/* We didn't find a pte */
if (ret == -EINVAL) {
/* Unsupported mmu config */
flags |= DSISR_UNSUPP_MMU;
} else if (ret == -ENOENT) {
/* No translation found */
flags |= DSISR_NOHPTE;
} else if (ret == -EFAULT) {
/* Couldn't access L1 real address */
flags |= DSISR_PRTABLE_FAULT;
vcpu->arch.fault_gpa = fault_addr;
} else {
/* Unknown error */
return ret;
}
goto forward_to_l1;
} else {
/* We found a pte -> check permissions */
if (dsisr & DSISR_ISSTORE) {
/* Can we write? */
if (!gpte_p->may_write) {
flags |= DSISR_PROTFAULT;
goto forward_to_l1;
}
} else if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
/* Can we execute? */
if (!gpte_p->may_execute) {
flags |= SRR1_ISI_N_G_OR_CIP;
goto forward_to_l1;
}
} else {
/* Can we read? */
if (!gpte_p->may_read && !gpte_p->may_write) {
flags |= DSISR_PROTFAULT;
goto forward_to_l1;
}
}
}
return 0;
forward_to_l1:
vcpu->arch.fault_dsisr = flags;
if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
vcpu->arch.shregs.msr &= SRR1_MSR_BITS;
vcpu->arch.shregs.msr |= flags;
}
return RESUME_HOST;
}
static long kvmhv_handle_nested_set_rc(struct kvm_vcpu *vcpu,
struct kvm_nested_guest *gp,
unsigned long n_gpa,
struct kvmppc_pte gpte,
unsigned long dsisr)
{
struct kvm *kvm = vcpu->kvm;
bool writing = !!(dsisr & DSISR_ISSTORE);
u64 pgflags;
long ret;
/* Are the rc bits set in the L1 partition scoped pte? */
pgflags = _PAGE_ACCESSED;
if (writing)
pgflags |= _PAGE_DIRTY;
if (pgflags & ~gpte.rc)
return RESUME_HOST;
spin_lock(&kvm->mmu_lock);
/* Set the rc bit in the pte of our (L0) pgtable for the L1 guest */
ret = kvmppc_hv_handle_set_rc(kvm, false, writing,
gpte.raddr, kvm->arch.lpid);
if (!ret) {
ret = -EINVAL;
goto out_unlock;
}
/* Set the rc bit in the pte of the shadow_pgtable for the nest guest */
ret = kvmppc_hv_handle_set_rc(kvm, true, writing,
n_gpa, gp->l1_lpid);
if (!ret)
ret = -EINVAL;
else
ret = 0;
out_unlock:
spin_unlock(&kvm->mmu_lock);
return ret;
}
static inline int kvmppc_radix_level_to_shift(int level)
{
switch (level) {
case 2:
return PUD_SHIFT;
case 1:
return PMD_SHIFT;
default:
return PAGE_SHIFT;
}
}
static inline int kvmppc_radix_shift_to_level(int shift)
{
if (shift == PUD_SHIFT)
return 2;
if (shift == PMD_SHIFT)
return 1;
if (shift == PAGE_SHIFT)
return 0;
WARN_ON_ONCE(1);
return 0;
}
/* called with gp->tlb_lock held */
static long int __kvmhv_nested_page_fault(struct kvm_vcpu *vcpu,
struct kvm_nested_guest *gp)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_memory_slot *memslot;
struct rmap_nested *n_rmap;
struct kvmppc_pte gpte;
pte_t pte, *pte_p;
unsigned long mmu_seq;
unsigned long dsisr = vcpu->arch.fault_dsisr;
unsigned long ea = vcpu->arch.fault_dar;
unsigned long *rmapp;
unsigned long n_gpa, gpa, gfn, perm = 0UL;
unsigned int shift, l1_shift, level;
bool writing = !!(dsisr & DSISR_ISSTORE);
bool kvm_ro = false;
long int ret;
if (!gp->l1_gr_to_hr) {
kvmhv_update_ptbl_cache(gp);
if (!gp->l1_gr_to_hr)
return RESUME_HOST;
}
/* Convert the nested guest real address into a L1 guest real address */
n_gpa = vcpu->arch.fault_gpa & ~0xF000000000000FFFULL;
if (!(dsisr & DSISR_PRTABLE_FAULT))
n_gpa |= ea & 0xFFF;
ret = kvmhv_translate_addr_nested(vcpu, gp, n_gpa, dsisr, &gpte);
/*
* If the hardware found a translation but we don't now have a usable
* translation in the l1 partition-scoped tree, remove the shadow pte
* and let the guest retry.
*/
if (ret == RESUME_HOST &&
(dsisr & (DSISR_PROTFAULT | DSISR_BADACCESS | DSISR_NOEXEC_OR_G |
DSISR_BAD_COPYPASTE)))
goto inval;
if (ret)
return ret;
/* Failed to set the reference/change bits */
if (dsisr & DSISR_SET_RC) {
ret = kvmhv_handle_nested_set_rc(vcpu, gp, n_gpa, gpte, dsisr);
if (ret == RESUME_HOST)
return ret;
if (ret)
goto inval;
dsisr &= ~DSISR_SET_RC;
if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
DSISR_PROTFAULT)))
return RESUME_GUEST;
}
/*
* We took an HISI or HDSI while we were running a nested guest which
* means we have no partition scoped translation for that. This means
* we need to insert a pte for the mapping into our shadow_pgtable.
*/
l1_shift = gpte.page_shift;
if (l1_shift < PAGE_SHIFT) {
/* We don't support l1 using a page size smaller than our own */
pr_err("KVM: L1 guest page shift (%d) less than our own (%d)\n",
l1_shift, PAGE_SHIFT);
return -EINVAL;
}
gpa = gpte.raddr;
gfn = gpa >> PAGE_SHIFT;
/* 1. Get the corresponding host memslot */
memslot = gfn_to_memslot(kvm, gfn);
if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS)) {
/* unusual error -> reflect to the guest as a DSI */
kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
return RESUME_GUEST;
}
/* passthrough of emulated MMIO case */
return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, writing);
}
if (memslot->flags & KVM_MEM_READONLY) {
if (writing) {
/* Give the guest a DSI */
kvmppc_core_queue_data_storage(vcpu, ea,
DSISR_ISSTORE | DSISR_PROTFAULT);
return RESUME_GUEST;
}
kvm_ro = true;
}
/* 2. Find the host pte for this L1 guest real address */
/* Used to check for invalidations in progress */
mmu_seq = kvm->mmu_notifier_seq;
smp_rmb();
/* See if can find translation in our partition scoped tables for L1 */
pte = __pte(0);
spin_lock(&kvm->mmu_lock);
pte_p = find_kvm_secondary_pte(kvm, gpa, &shift);
if (!shift)
shift = PAGE_SHIFT;
if (pte_p)
pte = *pte_p;
spin_unlock(&kvm->mmu_lock);
if (!pte_present(pte) || (writing && !(pte_val(pte) & _PAGE_WRITE))) {
/* No suitable pte found -> try to insert a mapping */
ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot,
writing, kvm_ro, &pte, &level);
if (ret == -EAGAIN)
return RESUME_GUEST;
else if (ret)
return ret;
shift = kvmppc_radix_level_to_shift(level);
}
/* Align gfn to the start of the page */
gfn = (gpa & ~((1UL << shift) - 1)) >> PAGE_SHIFT;
/* 3. Compute the pte we need to insert for nest_gpa -> host r_addr */
/* The permissions is the combination of the host and l1 guest ptes */
perm |= gpte.may_read ? 0UL : _PAGE_READ;
perm |= gpte.may_write ? 0UL : _PAGE_WRITE;
perm |= gpte.may_execute ? 0UL : _PAGE_EXEC;
/* Only set accessed/dirty (rc) bits if set in host and l1 guest ptes */
perm |= (gpte.rc & _PAGE_ACCESSED) ? 0UL : _PAGE_ACCESSED;
perm |= ((gpte.rc & _PAGE_DIRTY) && writing) ? 0UL : _PAGE_DIRTY;
pte = __pte(pte_val(pte) & ~perm);
/* What size pte can we insert? */
if (shift > l1_shift) {
u64 mask;
unsigned int actual_shift = PAGE_SHIFT;
if (PMD_SHIFT < l1_shift)
actual_shift = PMD_SHIFT;
mask = (1UL << shift) - (1UL << actual_shift);
pte = __pte(pte_val(pte) | (gpa & mask));
shift = actual_shift;
}
level = kvmppc_radix_shift_to_level(shift);
n_gpa &= ~((1UL << shift) - 1);
/* 4. Insert the pte into our shadow_pgtable */
n_rmap = kzalloc(sizeof(*n_rmap), GFP_KERNEL);
if (!n_rmap)
return RESUME_GUEST; /* Let the guest try again */
n_rmap->rmap = (n_gpa & RMAP_NESTED_GPA_MASK) |
(((unsigned long) gp->l1_lpid) << RMAP_NESTED_LPID_SHIFT);
rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
ret = kvmppc_create_pte(kvm, gp->shadow_pgtable, pte, n_gpa, level,
mmu_seq, gp->shadow_lpid, rmapp, &n_rmap);
kfree(n_rmap);
if (ret == -EAGAIN)
ret = RESUME_GUEST; /* Let the guest try again */
return ret;
inval:
kvmhv_invalidate_shadow_pte(vcpu, gp, n_gpa, NULL);
return RESUME_GUEST;
}
long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu)
{
struct kvm_nested_guest *gp = vcpu->arch.nested;
long int ret;
mutex_lock(&gp->tlb_lock);
ret = __kvmhv_nested_page_fault(vcpu, gp);
mutex_unlock(&gp->tlb_lock);
return ret;
}
int kvmhv_nested_next_lpid(struct kvm *kvm, int lpid)
{
int ret = -1;
spin_lock(&kvm->mmu_lock);
while (++lpid <= kvm->arch.max_nested_lpid) {
if (kvm->arch.nested_guests[lpid]) {
ret = lpid;
break;
}
}
spin_unlock(&kvm->mmu_lock);
return ret;
}
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