OpenCloudOS-Kernel/arch/x86/hyperv/mmu.c

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#define pr_fmt(fmt) "Hyper-V: " fmt
#include <linux/hyperv.h>
#include <linux/log2.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <asm/fpu/api.h>
#include <asm/mshyperv.h>
#include <asm/msr.h>
#include <asm/tlbflush.h>
#define CREATE_TRACE_POINTS
#include <asm/trace/hyperv.h>
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/* HvFlushVirtualAddressSpace, HvFlushVirtualAddressList hypercalls */
struct hv_flush_pcpu {
u64 address_space;
u64 flags;
u64 processor_mask;
u64 gva_list[];
};
/* HvFlushVirtualAddressSpaceEx, HvFlushVirtualAddressListEx hypercalls */
struct hv_flush_pcpu_ex {
u64 address_space;
u64 flags;
struct {
u64 format;
u64 valid_bank_mask;
u64 bank_contents[];
} hv_vp_set;
u64 gva_list[];
};
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/* Each gva in gva_list encodes up to 4096 pages to flush */
#define HV_TLB_FLUSH_UNIT (4096 * PAGE_SIZE)
static struct hv_flush_pcpu __percpu **pcpu_flush;
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static struct hv_flush_pcpu_ex __percpu **pcpu_flush_ex;
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/*
* Fills in gva_list starting from offset. Returns the number of items added.
*/
static inline int fill_gva_list(u64 gva_list[], int offset,
unsigned long start, unsigned long end)
{
int gva_n = offset;
unsigned long cur = start, diff;
do {
diff = end > cur ? end - cur : 0;
gva_list[gva_n] = cur & PAGE_MASK;
/*
* Lower 12 bits encode the number of additional
* pages to flush (in addition to the 'cur' page).
*/
if (diff >= HV_TLB_FLUSH_UNIT)
gva_list[gva_n] |= ~PAGE_MASK;
else if (diff)
gva_list[gva_n] |= (diff - 1) >> PAGE_SHIFT;
cur += HV_TLB_FLUSH_UNIT;
gva_n++;
} while (cur < end);
return gva_n - offset;
}
/* Return the number of banks in the resulting vp_set */
static inline int cpumask_to_vp_set(struct hv_flush_pcpu_ex *flush,
const struct cpumask *cpus)
{
int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
/* valid_bank_mask can represent up to 64 banks */
if (hv_max_vp_index / 64 >= 64)
return 0;
/*
* Clear all banks up to the maximum possible bank as hv_flush_pcpu_ex
* structs are not cleared between calls, we risk flushing unneeded
* vCPUs otherwise.
*/
for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++)
flush->hv_vp_set.bank_contents[vcpu_bank] = 0;
/*
* Some banks may end up being empty but this is acceptable.
*/
for_each_cpu(cpu, cpus) {
vcpu = hv_cpu_number_to_vp_number(cpu);
vcpu_bank = vcpu / 64;
vcpu_offset = vcpu % 64;
__set_bit(vcpu_offset, (unsigned long *)
&flush->hv_vp_set.bank_contents[vcpu_bank]);
if (vcpu_bank >= nr_bank)
nr_bank = vcpu_bank + 1;
}
flush->hv_vp_set.valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
return nr_bank;
}
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static void hyperv_flush_tlb_others(const struct cpumask *cpus,
const struct flush_tlb_info *info)
{
int cpu, vcpu, gva_n, max_gvas;
struct hv_flush_pcpu **flush_pcpu;
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struct hv_flush_pcpu *flush;
u64 status = U64_MAX;
unsigned long flags;
trace_hyperv_mmu_flush_tlb_others(cpus, info);
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if (!pcpu_flush || !hv_hypercall_pg)
goto do_native;
if (cpumask_empty(cpus))
return;
local_irq_save(flags);
flush_pcpu = this_cpu_ptr(pcpu_flush);
if (unlikely(!*flush_pcpu))
*flush_pcpu = page_address(alloc_page(GFP_ATOMIC));
flush = *flush_pcpu;
if (unlikely(!flush)) {
local_irq_restore(flags);
goto do_native;
}
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if (info->mm) {
flush->address_space = virt_to_phys(info->mm->pgd);
flush->flags = 0;
} else {
flush->address_space = 0;
flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
}
flush->processor_mask = 0;
if (cpumask_equal(cpus, cpu_present_mask)) {
flush->flags |= HV_FLUSH_ALL_PROCESSORS;
} else {
for_each_cpu(cpu, cpus) {
vcpu = hv_cpu_number_to_vp_number(cpu);
if (vcpu >= 64)
goto do_native;
__set_bit(vcpu, (unsigned long *)
&flush->processor_mask);
}
}
/*
* We can flush not more than max_gvas with one hypercall. Flush the
* whole address space if we were asked to do more.
*/
max_gvas = (PAGE_SIZE - sizeof(*flush)) / sizeof(flush->gva_list[0]);
if (info->end == TLB_FLUSH_ALL) {
flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
flush, NULL);
} else if (info->end &&
((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) {
status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
flush, NULL);
} else {
gva_n = fill_gva_list(flush->gva_list, 0,
info->start, info->end);
status = hv_do_rep_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST,
gva_n, 0, flush, NULL);
}
local_irq_restore(flags);
if (!(status & HV_HYPERCALL_RESULT_MASK))
return;
do_native:
native_flush_tlb_others(cpus, info);
}
static void hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
const struct flush_tlb_info *info)
{
int nr_bank = 0, max_gvas, gva_n;
struct hv_flush_pcpu_ex **flush_pcpu;
struct hv_flush_pcpu_ex *flush;
u64 status = U64_MAX;
unsigned long flags;
trace_hyperv_mmu_flush_tlb_others(cpus, info);
if (!pcpu_flush_ex || !hv_hypercall_pg)
goto do_native;
if (cpumask_empty(cpus))
return;
local_irq_save(flags);
flush_pcpu = this_cpu_ptr(pcpu_flush_ex);
if (unlikely(!*flush_pcpu))
*flush_pcpu = page_address(alloc_page(GFP_ATOMIC));
flush = *flush_pcpu;
if (unlikely(!flush)) {
local_irq_restore(flags);
goto do_native;
}
if (info->mm) {
flush->address_space = virt_to_phys(info->mm->pgd);
flush->flags = 0;
} else {
flush->address_space = 0;
flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
}
flush->hv_vp_set.valid_bank_mask = 0;
if (!cpumask_equal(cpus, cpu_present_mask)) {
flush->hv_vp_set.format = HV_GENERIC_SET_SPARCE_4K;
nr_bank = cpumask_to_vp_set(flush, cpus);
}
if (!nr_bank) {
flush->hv_vp_set.format = HV_GENERIC_SET_ALL;
flush->flags |= HV_FLUSH_ALL_PROCESSORS;
}
/*
* We can flush not more than max_gvas with one hypercall. Flush the
* whole address space if we were asked to do more.
*/
max_gvas =
(PAGE_SIZE - sizeof(*flush) - nr_bank *
sizeof(flush->hv_vp_set.bank_contents[0])) /
sizeof(flush->gva_list[0]);
if (info->end == TLB_FLUSH_ALL) {
flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
status = hv_do_rep_hypercall(
HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
0, nr_bank, flush, NULL);
} else if (info->end &&
((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) {
status = hv_do_rep_hypercall(
HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
0, nr_bank, flush, NULL);
} else {
gva_n = fill_gva_list(flush->gva_list, nr_bank,
info->start, info->end);
status = hv_do_rep_hypercall(
HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX,
gva_n, nr_bank, flush, NULL);
}
local_irq_restore(flags);
if (!(status & HV_HYPERCALL_RESULT_MASK))
return;
do_native:
native_flush_tlb_others(cpus, info);
}
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void hyperv_setup_mmu_ops(void)
{
if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED))
return;
setup_clear_cpu_cap(X86_FEATURE_PCID);
if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED)) {
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pr_info("Using hypercall for remote TLB flush\n");
pv_mmu_ops.flush_tlb_others = hyperv_flush_tlb_others;
} else {
pr_info("Using ext hypercall for remote TLB flush\n");
pv_mmu_ops.flush_tlb_others = hyperv_flush_tlb_others_ex;
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}
}
void hyper_alloc_mmu(void)
{
if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED))
return;
if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
pcpu_flush = alloc_percpu(struct hv_flush_pcpu *);
else
pcpu_flush_ex = alloc_percpu(struct hv_flush_pcpu_ex *);
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}