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- Add the necessary glue so that the kernel can run as a confidential 

SEV-SNP vTOM guest on Hyper-V. A vTOM guest basically splits the
   address space in two parts: encrypted and unencrypted. The use case
   being running unmodified guests on the Hyper-V confidential computing
   hypervisor
 
 - Double-buffer messages between the guest and the hardware PSP device
   so that no partial buffers are copied back'n'forth and thus potential
   message integrity and leak attacks are possible
 
 - Name the return value the sev-guest driver returns when the hw PSP
   device hasn't been called, explicitly
 
 - Cleanups
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Merge tag 'x86_sev_for_v6.4_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 SEV updates from Borislav Petkov:

 - Add the necessary glue so that the kernel can run as a confidential
   SEV-SNP vTOM guest on Hyper-V. A vTOM guest basically splits the
   address space in two parts: encrypted and unencrypted. The use case
   being running unmodified guests on the Hyper-V confidential computing
   hypervisor

 - Double-buffer messages between the guest and the hardware PSP device
   so that no partial buffers are copied back'n'forth and thus potential
   message integrity and leak attacks are possible

 - Name the return value the sev-guest driver returns when the hw PSP
   device hasn't been called, explicitly

 - Cleanups

* tag 'x86_sev_for_v6.4_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/hyperv: Change vTOM handling to use standard coco mechanisms
  init: Call mem_encrypt_init() after Hyper-V hypercall init is done
  x86/mm: Handle decryption/re-encryption of bss_decrypted consistently
  Drivers: hv: Explicitly request decrypted in vmap_pfn() calls
  x86/hyperv: Reorder code to facilitate future work
  x86/ioremap: Add hypervisor callback for private MMIO mapping in coco VM
  x86/sev: Change snp_guest_issue_request()'s fw_err argument
  virt/coco/sev-guest: Double-buffer messages
  crypto: ccp: Get rid of __sev_platform_init_locked()'s local function pointer
  crypto: ccp - Name -1 return value as SEV_RET_NO_FW_CALL
This commit is contained in:
Linus Torvalds 2023-04-25 10:48:08 -07:00
parent c42b59bfaa 812b0597fb
commit bc1bb2a49b
25 changed files with 311 additions and 168 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
Documentation/virt/coco/sev-guest.rst
View File

@ -37,11 +37,11 @@ along with a description:
the return value. General error numbers (-ENOMEM, -EINVAL)
are not detailed, but errors with specific meanings are.
The guest ioctl should be issued on a file descriptor of the /dev/sev-guest device.
The ioctl accepts struct snp_user_guest_request. The input and output structure is
specified through the req_data and resp_data field respectively. If the ioctl fails
to execute due to a firmware error, then fw_err code will be set otherwise the
fw_err will be set to 0x00000000000000ff.
The guest ioctl should be issued on a file descriptor of the /dev/sev-guest
device. The ioctl accepts struct snp_user_guest_request. The input and
output structure is specified through the req_data and resp_data field
respectively. If the ioctl fails to execute due to a firmware error, then
the fw_error code will be set, otherwise fw_error will be set to -1.
The firmware checks that the message sequence counter is one greater than
the guests message sequence counter. If guest driver fails to increment message
@ -57,8 +57,14 @@ counter (e.g. counter overflow), then -EIO will be returned.
__u64 req_data;
__u64 resp_data;
/* firmware error code on failure (see psp-sev.h) */
__u64 fw_err;
/* bits[63:32]: VMM error code, bits[31:0] firmware error code (see psp-sev.h) */
union {
__u64 exitinfo2;
struct {
__u32 fw_error;
__u32 vmm_error;
};
};
};
2.1 SNP_GET_REPORT

40
arch/x86/coco/core.c
View File

@ -29,6 +29,22 @@ static bool intel_cc_platform_has(enum cc_attr attr)
}
}
/*
* Handle the SEV-SNP vTOM case where sme_me_mask is zero, and
* the other levels of SME/SEV functionality, including C-bit
* based SEV-SNP, are not enabled.
*/
static __maybe_unused bool amd_cc_platform_vtom(enum cc_attr attr)
{
switch (attr) {
case CC_ATTR_GUEST_MEM_ENCRYPT:
case CC_ATTR_MEM_ENCRYPT:
return true;
default:
return false;
}
}
/*
* SME and SEV are very similar but they are not the same, so there are
* times that the kernel will need to distinguish between SME and SEV. The
@ -41,9 +57,14 @@ static bool intel_cc_platform_has(enum cc_attr attr)
* up under SME the trampoline area cannot be encrypted, whereas under SEV
* the trampoline area must be encrypted.
*/
static bool amd_cc_platform_has(enum cc_attr attr)
{
#ifdef CONFIG_AMD_MEM_ENCRYPT
if (sev_status & MSR_AMD64_SNP_VTOM)
return amd_cc_platform_vtom(attr);
switch (attr) {
case CC_ATTR_MEM_ENCRYPT:
return sme_me_mask;
@ -76,11 +97,6 @@ static bool amd_cc_platform_has(enum cc_attr attr)
#endif
}
static bool hyperv_cc_platform_has(enum cc_attr attr)
{
return attr == CC_ATTR_GUEST_MEM_ENCRYPT;
}
bool cc_platform_has(enum cc_attr attr)
{
switch (vendor) {
@ -88,8 +104,6 @@ bool cc_platform_has(enum cc_attr attr)
return amd_cc_platform_has(attr);
case CC_VENDOR_INTEL:
return intel_cc_platform_has(attr);
case CC_VENDOR_HYPERV:
return hyperv_cc_platform_has(attr);
default:
return false;
}
@ -103,11 +117,14 @@ u64 cc_mkenc(u64 val)
* encryption status of the page.
*
* - for AMD, bit *set* means the page is encrypted
* - for Intel *clear* means encrypted.
* - for AMD with vTOM and for Intel, *clear* means encrypted
*/
switch (vendor) {
case CC_VENDOR_AMD:
return val | cc_mask;
if (sev_status & MSR_AMD64_SNP_VTOM)
return val & ~cc_mask;
else
return val | cc_mask;
case CC_VENDOR_INTEL:
return val & ~cc_mask;
default:
@ -120,7 +137,10 @@ u64 cc_mkdec(u64 val)
/* See comment in cc_mkenc() */
switch (vendor) {
case CC_VENDOR_AMD:
return val & ~cc_mask;
if (sev_status & MSR_AMD64_SNP_VTOM)
return val | cc_mask;
else
return val & ~cc_mask;
case CC_VENDOR_INTEL:
return val | cc_mask;
default:

11
arch/x86/hyperv/hv_init.c
View File

@ -29,7 +29,6 @@
#include <linux/syscore_ops.h>
#include <clocksource/hyperv_timer.h>
#include <linux/highmem.h>
#include <linux/swiotlb.h>
int hyperv_init_cpuhp;
u64 hv_current_partition_id = ~0ull;
@ -504,16 +503,6 @@ void __init hyperv_init(void)
/* Query the VMs extended capability once, so that it can be cached. */
hv_query_ext_cap(0);
#ifdef CONFIG_SWIOTLB
/*
* Swiotlb bounce buffer needs to be mapped in extra address
* space. Map function doesn't work in the early place and so
* call swiotlb_update_mem_attributes() here.
*/
if (hv_is_isolation_supported())
swiotlb_update_mem_attributes();
#endif
return;
clean_guest_os_id:

142
arch/x86/hyperv/ivm.c
View File

@ -13,6 +13,8 @@
#include <asm/svm.h>
#include <asm/sev.h>
#include <asm/io.h>
#include <asm/coco.h>
#include <asm/mem_encrypt.h>
#include <asm/mshyperv.h>
#include <asm/hypervisor.h>
@ -233,41 +235,6 @@ void hv_ghcb_msr_read(u64 msr, u64 *value)
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(hv_ghcb_msr_read);
#endif
enum hv_isolation_type hv_get_isolation_type(void)
{
if (!(ms_hyperv.priv_high & HV_ISOLATION))
return HV_ISOLATION_TYPE_NONE;
return FIELD_GET(HV_ISOLATION_TYPE, ms_hyperv.isolation_config_b);
}
EXPORT_SYMBOL_GPL(hv_get_isolation_type);
/*
* hv_is_isolation_supported - Check system runs in the Hyper-V
* isolation VM.
*/
bool hv_is_isolation_supported(void)
{
if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
return false;
if (!hypervisor_is_type(X86_HYPER_MS_HYPERV))
return false;
return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
}
DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
/*
* hv_isolation_type_snp - Check system runs in the AMD SEV-SNP based
* isolation VM.
*/
bool hv_isolation_type_snp(void)
{
return static_branch_unlikely(&isolation_type_snp);
}
/*
* hv_mark_gpa_visibility - Set pages visible to host via hvcall.
@ -320,27 +287,25 @@ static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
}
/*
* hv_set_mem_host_visibility - Set specified memory visible to host.
* hv_vtom_set_host_visibility - Set specified memory visible to host.
*
* In Isolation VM, all guest memory is encrypted from host and guest
* needs to set memory visible to host via hvcall before sharing memory
* with host. This function works as wrap of hv_mark_gpa_visibility()
* with memory base and size.
*/
int hv_set_mem_host_visibility(unsigned long kbuffer, int pagecount, bool visible)
static bool hv_vtom_set_host_visibility(unsigned long kbuffer, int pagecount, bool enc)
{
enum hv_mem_host_visibility visibility = visible ?
VMBUS_PAGE_VISIBLE_READ_WRITE : VMBUS_PAGE_NOT_VISIBLE;
enum hv_mem_host_visibility visibility = enc ?
VMBUS_PAGE_NOT_VISIBLE : VMBUS_PAGE_VISIBLE_READ_WRITE;
u64 *pfn_array;
int ret = 0;
bool result = true;
int i, pfn;
if (!hv_is_isolation_supported() || !hv_hypercall_pg)
return 0;
pfn_array = kmalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
if (!pfn_array)
return -ENOMEM;
return false;
for (i = 0, pfn = 0; i < pagecount; i++) {
pfn_array[pfn] = virt_to_hvpfn((void *)kbuffer + i * HV_HYP_PAGE_SIZE);
@ -349,17 +314,68 @@ int hv_set_mem_host_visibility(unsigned long kbuffer, int pagecount, bool visibl
if (pfn == HV_MAX_MODIFY_GPA_REP_COUNT || i == pagecount - 1) {
ret = hv_mark_gpa_visibility(pfn, pfn_array,
visibility);
if (ret)
if (ret) {
result = false;
goto err_free_pfn_array;
}
pfn = 0;
}
}
err_free_pfn_array:
kfree(pfn_array);
return ret;
return result;
}
static bool hv_vtom_tlb_flush_required(bool private)
{
return true;
}
static bool hv_vtom_cache_flush_required(void)
{
return false;
}
static bool hv_is_private_mmio(u64 addr)
{
/*
* Hyper-V always provides a single IO-APIC in a guest VM.
* When a paravisor is used, it is emulated by the paravisor
* in the guest context and must be mapped private.
*/
if (addr >= HV_IOAPIC_BASE_ADDRESS &&
addr < (HV_IOAPIC_BASE_ADDRESS + PAGE_SIZE))
return true;
/* Same with a vTPM */
if (addr >= VTPM_BASE_ADDRESS &&
addr < (VTPM_BASE_ADDRESS + PAGE_SIZE))
return true;
return false;
}
void __init hv_vtom_init(void)
{
/*
* By design, a VM using vTOM doesn't see the SEV setting,
* so SEV initialization is bypassed and sev_status isn't set.
* Set it here to indicate a vTOM VM.
*/
sev_status = MSR_AMD64_SNP_VTOM;
cc_set_vendor(CC_VENDOR_AMD);
cc_set_mask(ms_hyperv.shared_gpa_boundary);
physical_mask &= ms_hyperv.shared_gpa_boundary - 1;
x86_platform.hyper.is_private_mmio = hv_is_private_mmio;
x86_platform.guest.enc_cache_flush_required = hv_vtom_cache_flush_required;
x86_platform.guest.enc_tlb_flush_required = hv_vtom_tlb_flush_required;
x86_platform.guest.enc_status_change_finish = hv_vtom_set_host_visibility;
}
#endif /* CONFIG_AMD_MEM_ENCRYPT */
/*
* hv_map_memory - map memory to extra space in the AMD SEV-SNP Isolation VM.
*/
@ -377,7 +393,7 @@ void *hv_map_memory(void *addr, unsigned long size)
pfns[i] = vmalloc_to_pfn(addr + i * PAGE_SIZE) +
(ms_hyperv.shared_gpa_boundary >> PAGE_SHIFT);
vaddr = vmap_pfn(pfns, size / PAGE_SIZE, PAGE_KERNEL_IO);
vaddr = vmap_pfn(pfns, size / PAGE_SIZE, pgprot_decrypted(PAGE_KERNEL));
kfree(pfns);
return vaddr;
@ -387,3 +403,37 @@ void hv_unmap_memory(void *addr)
{
vunmap(addr);
}
enum hv_isolation_type hv_get_isolation_type(void)
{
if (!(ms_hyperv.priv_high & HV_ISOLATION))
return HV_ISOLATION_TYPE_NONE;
return FIELD_GET(HV_ISOLATION_TYPE, ms_hyperv.isolation_config_b);
}
EXPORT_SYMBOL_GPL(hv_get_isolation_type);
/*
* hv_is_isolation_supported - Check system runs in the Hyper-V
* isolation VM.
*/
bool hv_is_isolation_supported(void)
{
if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
return false;
if (!hypervisor_is_type(X86_HYPER_MS_HYPERV))
return false;
return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
}
DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
/*
* hv_isolation_type_snp - Check system runs in the AMD SEV-SNP based
* isolation VM.
*/
bool hv_isolation_type_snp(void)
{
return static_branch_unlikely(&isolation_type_snp);
}

1
arch/x86/include/asm/coco.h
View File

@ -7,7 +7,6 @@
enum cc_vendor {
CC_VENDOR_NONE,
CC_VENDOR_AMD,
CC_VENDOR_HYPERV,
CC_VENDOR_INTEL,
};

1
arch/x86/include/asm/mem_encrypt.h
View File

@ -56,6 +56,7 @@ void __init sev_es_init_vc_handling(void);
#else /* !CONFIG_AMD_MEM_ENCRYPT */
#define sme_me_mask 0ULL
#define sev_status 0ULL
static inline void __init sme_early_encrypt(resource_size_t paddr,
unsigned long size) { }

16
arch/x86/include/asm/mshyperv.h
View File

@ -11,6 +11,14 @@
#include <asm/paravirt.h>
#include <asm/mshyperv.h>
/*
* Hyper-V always provides a single IO-APIC at this MMIO address.
* Ideally, the value should be looked up in ACPI tables, but it
* is needed for mapping the IO-APIC early in boot on Confidential
* VMs, before ACPI functions can be used.
*/
#define HV_IOAPIC_BASE_ADDRESS 0xfec00000
union hv_ghcb;
DECLARE_STATIC_KEY_FALSE(isolation_type_snp);
@ -206,18 +214,19 @@ struct irq_domain *hv_create_pci_msi_domain(void);
int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,
struct hv_interrupt_entry *entry);
int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry);
int hv_set_mem_host_visibility(unsigned long addr, int numpages, bool visible);
#ifdef CONFIG_AMD_MEM_ENCRYPT
void hv_ghcb_msr_write(u64 msr, u64 value);
void hv_ghcb_msr_read(u64 msr, u64 *value);
bool hv_ghcb_negotiate_protocol(void);
void hv_ghcb_terminate(unsigned int set, unsigned int reason);
void hv_vtom_init(void);
#else
static inline void hv_ghcb_msr_write(u64 msr, u64 value) {}
static inline void hv_ghcb_msr_read(u64 msr, u64 *value) {}
static inline bool hv_ghcb_negotiate_protocol(void) { return false; }
static inline void hv_ghcb_terminate(unsigned int set, unsigned int reason) {}
static inline void hv_vtom_init(void) {}
#endif
extern bool hv_isolation_type_snp(void);
@ -259,11 +268,6 @@ static inline void hv_set_register(unsigned int reg, u64 value) { }
static inline u64 hv_get_register(unsigned int reg) { return 0; }
static inline void hv_set_non_nested_register(unsigned int reg, u64 value) { }
static inline u64 hv_get_non_nested_register(unsigned int reg) { return 0; }
static inline int hv_set_mem_host_visibility(unsigned long addr, int numpages,
bool visible)
{
return -1;
}
#endif /* CONFIG_HYPERV */

4
arch/x86/include/asm/sev-common.h
View File

@ -128,10 +128,6 @@ struct snp_psc_desc {
struct psc_entry entries[VMGEXIT_PSC_MAX_ENTRY];
} __packed;
/* Guest message request error codes */
#define SNP_GUEST_REQ_INVALID_LEN BIT_ULL(32)
#define SNP_GUEST_REQ_ERR_BUSY BIT_ULL(33)
#define GHCB_MSR_TERM_REQ 0x100
#define GHCB_MSR_TERM_REASON_SET_POS 12
#define GHCB_MSR_TERM_REASON_SET_MASK 0xf

10
arch/x86/include/asm/sev.h
View File

@ -9,6 +9,8 @@
#define __ASM_ENCRYPTED_STATE_H
#include <linux/types.h>
#include <linux/sev-guest.h>
#include <asm/insn.h>
#include <asm/sev-common.h>
#include <asm/bootparam.h>
@ -185,6 +187,9 @@ static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate)
return rc;
}
struct snp_guest_request_ioctl;
void setup_ghcb(void);
void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
unsigned int npages);
@ -196,7 +201,7 @@ void snp_set_memory_private(unsigned long vaddr, unsigned int npages);
void snp_set_wakeup_secondary_cpu(void);
bool snp_init(struct boot_params *bp);
void __init __noreturn snp_abort(void);
int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned long *fw_err);
int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio);
#else
static inline void sev_es_ist_enter(struct pt_regs *regs) { }
static inline void sev_es_ist_exit(void) { }
@ -216,8 +221,7 @@ static inline void snp_set_memory_private(unsigned long vaddr, unsigned int npag
static inline void snp_set_wakeup_secondary_cpu(void) { }
static inline bool snp_init(struct boot_params *bp) { return false; }
static inline void snp_abort(void) { }
static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input,
unsigned long *fw_err)
static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio)
{
return -ENOTTY;
}

4
arch/x86/include/asm/x86_init.h
View File

@ -259,11 +259,15 @@ struct x86_legacy_features {
* VMMCALL under SEV-ES. Needs to return 'false'
* if the checks fail. Called from the #VC
* exception handler.
* @is_private_mmio: For CoCo VMs, must map MMIO address as private.
* Used when device is emulated by a paravisor
* layer in the VM context.
*/
struct x86_hyper_runtime {
void (*pin_vcpu)(int cpu);
void (*sev_es_hcall_prepare)(struct ghcb *ghcb, struct pt_regs *regs);
bool (*sev_es_hcall_finish)(struct ghcb *ghcb, struct pt_regs *regs);
bool (*is_private_mmio)(u64 addr);
};
/**

10
arch/x86/kernel/apic/io_apic.c
View File

@ -66,6 +66,7 @@
#include <asm/hw_irq.h>
#include <asm/apic.h>
#include <asm/pgtable.h>
#include <asm/x86_init.h>
#define for_each_ioapic(idx) \
for ((idx) = 0; (idx) < nr_ioapics; (idx)++)
@ -2680,10 +2681,15 @@ static void io_apic_set_fixmap(enum fixed_addresses idx, phys_addr_t phys)
pgprot_t flags = FIXMAP_PAGE_NOCACHE;
/*
* Ensure fixmaps for IOAPIC MMIO respect memory encryption pgprot
* Ensure fixmaps for IO-APIC MMIO respect memory encryption pgprot
* bits, just like normal ioremap():
*/
flags = pgprot_decrypted(flags);
if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) {
if (x86_platform.hyper.is_private_mmio(phys))
flags = pgprot_encrypted(flags);
else
flags = pgprot_decrypted(flags);
}
__set_fixmap(idx, phys, flags);
}

15
arch/x86/kernel/cpu/mshyperv.c
View File

@ -33,7 +33,6 @@
#include <asm/nmi.h>
#include <clocksource/hyperv_timer.h>
#include <asm/numa.h>
#include <asm/coco.h>
/* Is Linux running as the root partition? */
bool hv_root_partition;
@ -401,8 +400,10 @@ static void __init ms_hyperv_init_platform(void)
if (ms_hyperv.priv_high & HV_ISOLATION) {
ms_hyperv.isolation_config_a = cpuid_eax(HYPERV_CPUID_ISOLATION_CONFIG);
ms_hyperv.isolation_config_b = cpuid_ebx(HYPERV_CPUID_ISOLATION_CONFIG);
ms_hyperv.shared_gpa_boundary =
BIT_ULL(ms_hyperv.shared_gpa_boundary_bits);
if (ms_hyperv.shared_gpa_boundary_active)
ms_hyperv.shared_gpa_boundary =
BIT_ULL(ms_hyperv.shared_gpa_boundary_bits);
pr_info("Hyper-V: Isolation Config: Group A 0x%x, Group B 0x%x\n",
ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b);
@ -413,11 +414,6 @@ static void __init ms_hyperv_init_platform(void)
swiotlb_unencrypted_base = ms_hyperv.shared_gpa_boundary;
#endif
}
/* Isolation VMs are unenlightened SEV-based VMs, thus this check: */
if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
if (hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE)
cc_set_vendor(CC_VENDOR_HYPERV);
}
}
if (hv_max_functions_eax >= HYPERV_CPUID_NESTED_FEATURES) {
@ -486,6 +482,9 @@ static void __init ms_hyperv_init_platform(void)
i8253_clear_counter_on_shutdown = false;
#if IS_ENABLED(CONFIG_HYPERV)
if ((hv_get_isolation_type() == HV_ISOLATION_TYPE_VBS) ||
(hv_get_isolation_type() == HV_ISOLATION_TYPE_SNP))
hv_vtom_init();
/*
* Setup the hook to get control post apic initialization.
*/

15
arch/x86/kernel/sev.c
View File

@ -22,6 +22,8 @@
#include <linux/efi.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/psp-sev.h>
#include <uapi/linux/sev-guest.h>
#include <asm/cpu_entry_area.h>
#include <asm/stacktrace.h>
@ -2175,7 +2177,7 @@ static int __init init_sev_config(char *str)
}
__setup("sev=", init_sev_config);
int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned long *fw_err)
int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio)
{
struct ghcb_state state;
struct es_em_ctxt ctxt;
@ -2183,8 +2185,7 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned
struct ghcb *ghcb;
int ret;
if (!fw_err)
return -EINVAL;
rio->exitinfo2 = SEV_RET_NO_FW_CALL;
/*
* __sev_get_ghcb() needs to run with IRQs disabled because it is using
@ -2209,16 +2210,16 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned
if (ret)
goto e_put;
*fw_err = ghcb->save.sw_exit_info_2;
switch (*fw_err) {
rio->exitinfo2 = ghcb->save.sw_exit_info_2;
switch (rio->exitinfo2) {
case 0:
break;
case SNP_GUEST_REQ_ERR_BUSY:
case SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_BUSY):
ret = -EAGAIN;
break;
case SNP_GUEST_REQ_INVALID_LEN:
case SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN):
/* Number of expected pages are returned in RBX */
if (exit_code == SVM_VMGEXIT_EXT_GUEST_REQUEST) {
input->data_npages = ghcb_get_rbx(ghcb);

2
arch/x86/kernel/x86_init.c
View File

@ -134,6 +134,7 @@ static void enc_status_change_prepare_noop(unsigned long vaddr, int npages, bool
static bool enc_status_change_finish_noop(unsigned long vaddr, int npages, bool enc) { return false; }
static bool enc_tlb_flush_required_noop(bool enc) { return false; }
static bool enc_cache_flush_required_noop(void) { return false; }
static bool is_private_mmio_noop(u64 addr) {return false; }
struct x86_platform_ops x86_platform __ro_after_init = {
.calibrate_cpu = native_calibrate_cpu_early,
@ -149,6 +150,7 @@ struct x86_platform_ops x86_platform __ro_after_init = {
.realmode_reserve = reserve_real_mode,
.realmode_init = init_real_mode,
.hyper.pin_vcpu = x86_op_int_noop,
.hyper.is_private_mmio = is_private_mmio_noop,
.guest = {
.enc_status_change_prepare = enc_status_change_prepare_noop,

5
arch/x86/mm/ioremap.c
View File

@ -116,6 +116,11 @@ static void __ioremap_check_other(resource_size_t addr, struct ioremap_desc *des
if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
return;
if (x86_platform.hyper.is_private_mmio(addr)) {
desc->flags |= IORES_MAP_ENCRYPTED;
return;
}
if (!IS_ENABLED(CONFIG_EFI))
return;

10
arch/x86/mm/mem_encrypt_amd.c
View File

@ -513,10 +513,14 @@ void __init mem_encrypt_free_decrypted_mem(void)
npages = (vaddr_end - vaddr) >> PAGE_SHIFT;
/*
* The unused memory range was mapped decrypted, change the encryption
* attribute from decrypted to encrypted before freeing it.
* If the unused memory range was mapped decrypted, change the encryption
* attribute from decrypted to encrypted before freeing it. Base the
* re-encryption on the same condition used for the decryption in
* sme_postprocess_startup(). Higher level abstractions, such as
* CC_ATTR_MEM_ENCRYPT, aren't necessarily equivalent in a Hyper-V VM
* using vTOM, where sme_me_mask is always zero.
*/
if (cc_platform_has(CC_ATTR_MEM_ENCRYPT)) {
if (sme_me_mask) {
r = set_memory_encrypted(vaddr, npages);
if (r) {
pr_warn("failed to free unused decrypted pages\n");

3
arch/x86/mm/pat/set_memory.c
View File

@ -2175,9 +2175,6 @@ static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc)
static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
{
if (hv_is_isolation_supported())
return hv_set_mem_host_visibility(addr, numpages, !enc);
if (cc_platform_has(CC_ATTR_MEM_ENCRYPT))
return __set_memory_enc_pgtable(addr, numpages, enc);

22
drivers/crypto/ccp/sev-dev.c
View File

@ -442,12 +442,19 @@ static int __sev_init_ex_locked(int *error)
return __sev_do_cmd_locked(SEV_CMD_INIT_EX, &data, error);
}
static inline int __sev_do_init_locked(int *psp_ret)
{
if (sev_init_ex_buffer)
return __sev_init_ex_locked(psp_ret);
else
return __sev_init_locked(psp_ret);
}
static int __sev_platform_init_locked(int *error)
{
int rc = 0, psp_ret = SEV_RET_NO_FW_CALL;
struct psp_device *psp = psp_master;
struct sev_device *sev;
int rc = 0, psp_ret = -1;
int (*init_function)(int *error);
if (!psp || !psp->sev_data)
return -ENODEV;
@ -458,15 +465,12 @@ static int __sev_platform_init_locked(int *error)
return 0;
if (sev_init_ex_buffer) {
init_function = __sev_init_ex_locked;
rc = sev_read_init_ex_file();
if (rc)
return rc;
} else {
init_function = __sev_init_locked;
}
rc = init_function(&psp_ret);
rc = __sev_do_init_locked(&psp_ret);
if (rc && psp_ret == SEV_RET_SECURE_DATA_INVALID) {
/*
* Initialization command returned an integrity check failure
@ -475,9 +479,11 @@ static int __sev_platform_init_locked(int *error)
* initialization function should succeed by replacing the state
* with a reset state.
*/
dev_err(sev->dev, "SEV: retrying INIT command because of SECURE_DATA_INVALID error. Retrying once to reset PSP SEV state.");
rc = init_function(&psp_ret);
dev_err(sev->dev,
"SEV: retrying INIT command because of SECURE_DATA_INVALID error. Retrying once to reset PSP SEV state.");
rc = __sev_do_init_locked(&psp_ret);
}
if (error)
*error = psp_ret;

2
drivers/hv/ring_buffer.c
View File

@ -211,7 +211,7 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
ring_info->ring_buffer = (struct hv_ring_buffer *)
vmap_pfn(pfns_wraparound, page_cnt * 2 - 1,
PAGE_KERNEL);
pgprot_decrypted(PAGE_KERNEL));
kfree(pfns_wraparound);
if (!ring_info->ring_buffer)

1
drivers/hv/vmbus_drv.c
View File

@ -2156,7 +2156,6 @@ void vmbus_device_unregister(struct hv_device *device_obj)
* VMBUS is an acpi enumerated device. Get the information we
* need from DSDT.
*/
#define VTPM_BASE_ADDRESS 0xfed40000
static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
{
resource_size_t start = 0;

99
drivers/virt/coco/sev-guest/sev-guest.c
View File

@ -46,7 +46,15 @@ struct snp_guest_dev {
void *certs_data;
struct snp_guest_crypto *crypto;
/* request and response are in unencrypted memory */
struct snp_guest_msg *request, *response;
/*
* Avoid information leakage by double-buffering shared messages
* in fields that are in regular encrypted memory.
*/
struct snp_guest_msg secret_request, secret_response;
struct snp_secrets_page_layout *layout;
struct snp_req_data input;
u32 *os_area_msg_seqno;
@ -266,14 +274,17 @@ static int dec_payload(struct snp_guest_dev *snp_dev, struct snp_guest_msg *msg,
static int verify_and_dec_payload(struct snp_guest_dev *snp_dev, void *payload, u32 sz)
{
struct snp_guest_crypto *crypto = snp_dev->crypto;
struct snp_guest_msg *resp = snp_dev->response;
struct snp_guest_msg *req = snp_dev->request;
struct snp_guest_msg *resp = &snp_dev->secret_response;
struct snp_guest_msg *req = &snp_dev->secret_request;
struct snp_guest_msg_hdr *req_hdr = &req->hdr;
struct snp_guest_msg_hdr *resp_hdr = &resp->hdr;
dev_dbg(snp_dev->dev, "response [seqno %lld type %d version %d sz %d]\n",
resp_hdr->msg_seqno, resp_hdr->msg_type, resp_hdr->msg_version, resp_hdr->msg_sz);
/* Copy response from shared memory to encrypted memory. */
memcpy(resp, snp_dev->response, sizeof(*resp));
/* Verify that the sequence counter is incremented by 1 */
if (unlikely(resp_hdr->msg_seqno != (req_hdr->msg_seqno + 1)))
return -EBADMSG;
@ -297,7 +308,7 @@ static int verify_and_dec_payload(struct snp_guest_dev *snp_dev, void *payload,
static int enc_payload(struct snp_guest_dev *snp_dev, u64 seqno, int version, u8 type,
void *payload, size_t sz)
{
struct snp_guest_msg *req = snp_dev->request;
struct snp_guest_msg *req = &snp_dev->secret_request;
struct snp_guest_msg_hdr *hdr = &req->hdr;
memset(req, 0, sizeof(*req));
@ -321,11 +332,12 @@ static int enc_payload(struct snp_guest_dev *snp_dev, u64 seqno, int version, u8
return __enc_payload(snp_dev, req, payload, sz);
}
static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, __u64 *fw_err)
static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
struct snp_guest_request_ioctl *rio)
{
unsigned long err = 0xff, override_err = 0;
unsigned long req_start = jiffies;
unsigned int override_npages = 0;
u64 override_err = 0;
int rc;
retry_request:
@ -335,7 +347,7 @@ retry_request:
* sequence number must be incremented or the VMPCK must be deleted to
* prevent reuse of the IV.
*/
rc = snp_issue_guest_request(exit_code, &snp_dev->input, &err);
rc = snp_issue_guest_request(exit_code, &snp_dev->input, rio);
switch (rc) {
case -ENOSPC:
/*
@ -353,7 +365,7 @@ retry_request:
* request buffer size was too small and give the caller the
* required buffer size.
*/
override_err = SNP_GUEST_REQ_INVALID_LEN;
override_err = SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN);
/*
* If this call to the firmware succeeds, the sequence number can
@ -366,7 +378,7 @@ retry_request:
goto retry_request;
/*
* The host may return SNP_GUEST_REQ_ERR_EBUSY if the request has been
* The host may return SNP_GUEST_VMM_ERR_BUSY if the request has been
* throttled. Retry in the driver to avoid returning and reusing the
* message sequence number on a different message.
*/
@ -387,27 +399,29 @@ retry_request:
*/
snp_inc_msg_seqno(snp_dev);
if (fw_err)
*fw_err = override_err ?: err;
if (override_err) {
rio->exitinfo2 = override_err;
/*
* If an extended guest request was issued and the supplied certificate
* buffer was not large enough, a standard guest request was issued to
* prevent IV reuse. If the standard request was successful, return -EIO
* back to the caller as would have originally been returned.
*/
if (!rc && override_err == SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN))
rc = -EIO;
}
if (override_npages)
snp_dev->input.data_npages = override_npages;
/*
* If an extended guest request was issued and the supplied certificate
* buffer was not large enough, a standard guest request was issued to
* prevent IV reuse. If the standard request was successful, return -EIO
* back to the caller as would have originally been returned.
*/
if (!rc && override_err == SNP_GUEST_REQ_INVALID_LEN)
return -EIO;
return rc;
}
static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, int msg_ver,
u8 type, void *req_buf, size_t req_sz, void *resp_buf,
u32 resp_sz, __u64 *fw_err)
static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code,
struct snp_guest_request_ioctl *rio, u8 type,
void *req_buf, size_t req_sz, void *resp_buf,
u32 resp_sz)
{
u64 seqno;
int rc;
@ -417,19 +431,31 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in
if (!seqno)
return -EIO;
/* Clear shared memory's response for the host to populate. */
memset(snp_dev->response, 0, sizeof(struct snp_guest_msg));
/* Encrypt the userspace provided payload */
rc = enc_payload(snp_dev, seqno, msg_ver, type, req_buf, req_sz);
/* Encrypt the userspace provided payload in snp_dev->secret_request. */
rc = enc_payload(snp_dev, seqno, rio->msg_version, type, req_buf, req_sz);
if (rc)
return rc;
rc = __handle_guest_request(snp_dev, exit_code, fw_err);
/*
* Write the fully encrypted request to the shared unencrypted
* request page.
*/
memcpy(snp_dev->request, &snp_dev->secret_request,
sizeof(snp_dev->secret_request));
rc = __handle_guest_request(snp_dev, exit_code, rio);
if (rc) {
if (rc == -EIO && *fw_err == SNP_GUEST_REQ_INVALID_LEN)
if (rc == -EIO &&
rio->exitinfo2 == SNP_GUEST_VMM_ERR(SNP_GUEST_VMM_ERR_INVALID_LEN))
return rc;
dev_alert(snp_dev->dev, "Detected error from ASP request. rc: %d, fw_err: %llu\n", rc, *fw_err);
dev_alert(snp_dev->dev,
"Detected error from ASP request. rc: %d, exitinfo2: 0x%llx\n",
rc, rio->exitinfo2);
snp_disable_vmpck(snp_dev);
return rc;
}
@ -469,9 +495,9 @@ static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_io
if (!resp)
return -ENOMEM;
rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg->msg_version,
rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg,
SNP_MSG_REPORT_REQ, &req, sizeof(req), resp->data,
resp_len, &arg->fw_err);
resp_len);
if (rc)
goto e_free;
@ -509,9 +535,8 @@ static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque
if (copy_from_user(&req, (void __user *)arg->req_data, sizeof(req)))
return -EFAULT;
rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg->msg_version,
SNP_MSG_KEY_REQ, &req, sizeof(req), buf, resp_len,
&arg->fw_err);
rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg,
SNP_MSG_KEY_REQ, &req, sizeof(req), buf, resp_len);
if (rc)
return rc;
@ -571,12 +596,12 @@ cmd:
return -ENOMEM;
snp_dev->input.data_npages = npages;
ret = handle_guest_request(snp_dev, SVM_VMGEXIT_EXT_GUEST_REQUEST, arg->msg_version,
ret = handle_guest_request(snp_dev, SVM_VMGEXIT_EXT_GUEST_REQUEST, arg,
SNP_MSG_REPORT_REQ, &req.data,
sizeof(req.data), resp->data, resp_len, &arg->fw_err);
sizeof(req.data), resp->data, resp_len);
/* If certs length is invalid then copy the returned length */
if (arg->fw_err == SNP_GUEST_REQ_INVALID_LEN) {
if (arg->vmm_error == SNP_GUEST_VMM_ERR_INVALID_LEN) {
req.certs_len = snp_dev->input.data_npages << PAGE_SHIFT;
if (copy_to_user((void __user *)arg->req_data, &req, sizeof(req)))
@ -611,7 +636,7 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
if (copy_from_user(&input, argp, sizeof(input)))
return -EFAULT;
input.fw_err = 0xff;
input.exitinfo2 = 0xff;
/* Message version must be non-zero */
if (!input.msg_version)
@ -642,7 +667,7 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
mutex_unlock(&snp_cmd_mutex);
if (input.fw_err && copy_to_user(argp, &input, sizeof(input)))
if (input.exitinfo2 && copy_to_user(argp, &input, sizeof(input)))
return -EFAULT;
return ret;

2
include/asm-generic/mshyperv.h
View File

@ -26,6 +26,8 @@
#include <asm/ptrace.h>
#include <asm/hyperv-tlfs.h>
#define VTPM_BASE_ADDRESS 0xfed40000
struct ms_hyperv_info {
u32 features;
u32 priv_high;

7
include/uapi/linux/psp-sev.h
View File

@ -36,6 +36,13 @@ enum {
* SEV Firmware status code
*/
typedef enum {
/*
* This error code is not in the SEV spec. Its purpose is to convey that
* there was an error that prevented the SEV firmware from being called.
* The SEV API error codes are 16 bits, so the -1 value will not overlap
* with possible values from the specification.
*/
SEV_RET_NO_FW_CALL = -1,
SEV_RET_SUCCESS = 0,
SEV_RET_INVALID_PLATFORM_STATE,
SEV_RET_INVALID_GUEST_STATE,

18
include/uapi/linux/sev-guest.h
View File

@ -52,8 +52,14 @@ struct snp_guest_request_ioctl {
__u64 req_data;
__u64 resp_data;
/* firmware error code on failure (see psp-sev.h) */
__u64 fw_err;
/* bits[63:32]: VMM error code, bits[31:0] firmware error code (see psp-sev.h) */
union {
__u64 exitinfo2;
struct {
__u32 fw_error;
__u32 vmm_error;
};
};
};
struct snp_ext_report_req {
@ -77,4 +83,12 @@ struct snp_ext_report_req {
/* Get SNP extended report as defined in the GHCB specification version 2. */
#define SNP_GET_EXT_REPORT _IOWR(SNP_GUEST_REQ_IOC_TYPE, 0x2, struct snp_guest_request_ioctl)
/* Guest message request EXIT_INFO_2 constants */
#define SNP_GUEST_FW_ERR_MASK GENMASK_ULL(31, 0)
#define SNP_GUEST_VMM_ERR_SHIFT 32
#define SNP_GUEST_VMM_ERR(x) (((u64)x) << SNP_GUEST_VMM_ERR_SHIFT)
#define SNP_GUEST_VMM_ERR_INVALID_LEN 1
#define SNP_GUEST_VMM_ERR_BUSY 2
#endif /* __UAPI_LINUX_SEV_GUEST_H_ */

19
init/main.c
View File

@ -1092,14 +1092,6 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
*/
locking_selftest();
/*
* This needs to be called before any devices perform DMA
* operations that might use the SWIOTLB bounce buffers. It will
* mark the bounce buffers as decrypted so that their usage will
* not cause "plain-text" data to be decrypted when accessed.
*/
mem_encrypt_init();
#ifdef CONFIG_BLK_DEV_INITRD
if (initrd_start && !initrd_below_start_ok &&
page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
@ -1116,6 +1108,17 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
late_time_init();
sched_clock_init();
calibrate_delay();
/*
* This needs to be called before any devices perform DMA
* operations that might use the SWIOTLB bounce buffers. It will
* mark the bounce buffers as decrypted so that their usage will
* not cause "plain-text" data to be decrypted when accessed. It
* must be called after late_time_init() so that Hyper-V x86/x64
* hypercalls work when the SWIOTLB bounce buffers are decrypted.
*/
mem_encrypt_init();
pid_idr_init();
anon_vma_init();
#ifdef CONFIG_X86