| Message ID | 4ca573363fb8fcd970add90fad4b51d43f1c5d84.1618254007.git.ashish.kalra@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add AMD SEV guest live migration support | expand |
On Mon, Apr 12, 2021 at 12:46 PM Ashish Kalra <Ashish.Kalra@amd.com> wrote: > > From: Ashish Kalra <ashish.kalra@amd.com> > > The guest support for detecting and enabling SEV Live migration > feature uses the following logic : > > - kvm_init_plaform() invokes check_kvm_sev_migration() which > checks if its booted under the EFI > > - If not EFI, > > i) check for the KVM_FEATURE_CPUID > > ii) if CPUID reports that migration is supported, issue a wrmsrl() > to enable the SEV live migration support > > - If EFI, > > i) check for the KVM_FEATURE_CPUID > > ii) If CPUID reports that migration is supported, read the UEFI variable which > indicates OVMF support for live migration > > iii) the variable indicates live migration is supported, issue a wrmsrl() to > enable the SEV live migration support > > The EFI live migration check is done using a late_initcall() callback. > > Also, ensure that _bss_decrypted section is marked as decrypted in the > shared pages list. > > Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> > --- > arch/x86/include/asm/mem_encrypt.h | 8 +++++ > arch/x86/kernel/kvm.c | 52 ++++++++++++++++++++++++++++++ > arch/x86/mm/mem_encrypt.c | 41 +++++++++++++++++++++++ > 3 files changed, 101 insertions(+) > > diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h > index 31c4df123aa0..19b77f3a62dc 100644 > --- a/arch/x86/include/asm/mem_encrypt.h > +++ b/arch/x86/include/asm/mem_encrypt.h > @@ -21,6 +21,7 @@ > extern u64 sme_me_mask; > extern u64 sev_status; > extern bool sev_enabled; > +extern bool sev_live_migration_enabled; > > void sme_encrypt_execute(unsigned long encrypted_kernel_vaddr, > unsigned long decrypted_kernel_vaddr, > @@ -44,8 +45,11 @@ void __init sme_enable(struct boot_params *bp); > > int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size); > int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size); > +void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages, > + bool enc); > > void __init mem_encrypt_free_decrypted_mem(void); > +void __init check_kvm_sev_migration(void); > > /* Architecture __weak replacement functions */ > void __init mem_encrypt_init(void); > @@ -60,6 +64,7 @@ bool sev_es_active(void); > #else /* !CONFIG_AMD_MEM_ENCRYPT */ > > #define sme_me_mask 0ULL > +#define sev_live_migration_enabled false > > static inline void __init sme_early_encrypt(resource_size_t paddr, > unsigned long size) { } > @@ -84,8 +89,11 @@ static inline int __init > early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; } > static inline int __init > early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { return 0; } > +static inline void __init > +early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages, bool enc) {} > > static inline void mem_encrypt_free_decrypted_mem(void) { } > +static inline void check_kvm_sev_migration(void) { } > > #define __bss_decrypted > > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c > index 78bb0fae3982..bcc82e0c9779 100644 > --- a/arch/x86/kernel/kvm.c > +++ b/arch/x86/kernel/kvm.c > @@ -26,6 +26,7 @@ > #include <linux/kprobes.h> > #include <linux/nmi.h> > #include <linux/swait.h> > +#include <linux/efi.h> > #include <asm/timer.h> > #include <asm/cpu.h> > #include <asm/traps.h> > @@ -429,6 +430,56 @@ static inline void __set_percpu_decrypted(void *ptr, unsigned long size) > early_set_memory_decrypted((unsigned long) ptr, size); > } > > +static int __init setup_kvm_sev_migration(void) > +{ > + efi_char16_t efi_sev_live_migration_enabled[] = L"SevLiveMigrationEnabled"; > + efi_guid_t efi_variable_guid = MEM_ENCRYPT_GUID; > + efi_status_t status; > + unsigned long size; > + bool enabled; > + > + /* > + * check_kvm_sev_migration() invoked via kvm_init_platform() before > + * this callback would have setup the indicator that live migration > + * feature is supported/enabled. > + */ > + if (!sev_live_migration_enabled) > + return 0; > + > + if (!efi_enabled(EFI_RUNTIME_SERVICES)) { > + pr_info("%s : EFI runtime services are not enabled\n", __func__); > + return 0; > + } > + > + size = sizeof(enabled); > + > + /* Get variable contents into buffer */ > + status = efi.get_variable(efi_sev_live_migration_enabled, > + &efi_variable_guid, NULL, &size, &enabled); > + > + if (status == EFI_NOT_FOUND) { > + pr_info("%s : EFI live migration variable not found\n", __func__); > + return 0; > + } > + > + if (status != EFI_SUCCESS) { > + pr_info("%s : EFI variable retrieval failed\n", __func__); > + return 0; > + } > + > + if (enabled == 0) { > + pr_info("%s: live migration disabled in EFI\n", __func__); > + return 0; > + } > + > + pr_info("%s : live migration enabled in EFI\n", __func__); > + wrmsrl(MSR_KVM_SEV_LIVE_MIGRATION, KVM_SEV_LIVE_MIGRATION_ENABLED); > + > + return true; > +} > + > +late_initcall(setup_kvm_sev_migration); > + > /* > * Iterate through all possible CPUs and map the memory region pointed > * by apf_reason, steal_time and kvm_apic_eoi as decrypted at once. > @@ -747,6 +798,7 @@ static bool __init kvm_msi_ext_dest_id(void) > > static void __init kvm_init_platform(void) > { > + check_kvm_sev_migration(); > kvmclock_init(); > x86_platform.apic_post_init = kvm_apic_init; > } > diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c > index fae9ccbd0da7..4de417333c09 100644 > --- a/arch/x86/mm/mem_encrypt.c > +++ b/arch/x86/mm/mem_encrypt.c > @@ -20,6 +20,7 @@ > #include <linux/bitops.h> > #include <linux/dma-mapping.h> > #include <linux/kvm_para.h> > +#include <linux/efi.h> > > #include <asm/tlbflush.h> > #include <asm/fixmap.h> > @@ -48,6 +49,8 @@ EXPORT_SYMBOL_GPL(sev_enable_key); > > bool sev_enabled __section(".data"); > > +bool sev_live_migration_enabled __section(".data"); > + > /* Buffer used for early in-place encryption by BSP, no locking needed */ > static char sme_early_buffer[PAGE_SIZE] __initdata __aligned(PAGE_SIZE); > > @@ -237,6 +240,9 @@ static void set_memory_enc_dec_hypercall(unsigned long vaddr, int npages, > unsigned long sz = npages << PAGE_SHIFT; > unsigned long vaddr_end, vaddr_next; > > + if (!sev_live_migration_enabled) > + return; > + > vaddr_end = vaddr + sz; > > for (; vaddr < vaddr_end; vaddr = vaddr_next) { > @@ -407,6 +413,12 @@ int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size) > return early_set_memory_enc_dec(vaddr, size, true); > } > > +void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages, > + bool enc) > +{ > + set_memory_enc_dec_hypercall(vaddr, npages, enc); > +} > + > /* > * 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 > @@ -462,6 +474,35 @@ bool force_dma_unencrypted(struct device *dev) > return false; > } > > +void __init check_kvm_sev_migration(void) > +{ > + if (sev_active() && > + kvm_para_has_feature(KVM_FEATURE_SEV_LIVE_MIGRATION)) { > + unsigned long nr_pages; > + > + pr_info("KVM enable live migration\n"); > + sev_live_migration_enabled = true; > + > + /* > + * Ensure that _bss_decrypted section is marked as decrypted in the > + * shared pages list. > + */ > + nr_pages = DIV_ROUND_UP(__end_bss_decrypted - __start_bss_decrypted, > + PAGE_SIZE); > + early_set_mem_enc_dec_hypercall((unsigned long)__start_bss_decrypted, > + nr_pages, 0); > + > + /* > + * If not booted using EFI, enable Live migration support. > + */ > + if (!efi_enabled(EFI_BOOT)) > + wrmsrl(MSR_KVM_SEV_LIVE_MIGRATION, > + KVM_SEV_LIVE_MIGRATION_ENABLED); > + } else { > + pr_info("KVM enable live migration feature unsupported\n"); I might be misunderstanding this, but I'm not sure this log message is correct: isn't the intention that the late initcall will be the one to check if this should be enabled later in this case? I have a similar question above about the log message after "!efi_enabled(EFI_RUNTIME_SERVICES)": shouldn't that avoid logging if !efi_enabled(EFI_BOOT) (since the wrmsl call already had been made here?) > + } > +} > + > void __init mem_encrypt_free_decrypted_mem(void) > { > unsigned long vaddr, vaddr_end, npages; > -- > 2.17.1 > Other than these: Reviewed-by: Steve Rutherford <srutherford@google.com>
On Mon, Apr 12, 2021 at 05:25:15PM -0700, Steve Rutherford wrote: > On Mon, Apr 12, 2021 at 12:46 PM Ashish Kalra <Ashish.Kalra@amd.com> wrote: > > > > From: Ashish Kalra <ashish.kalra@amd.com> > > > > The guest support for detecting and enabling SEV Live migration > > feature uses the following logic : > > > > - kvm_init_plaform() invokes check_kvm_sev_migration() which > > checks if its booted under the EFI > > > > - If not EFI, > > > > i) check for the KVM_FEATURE_CPUID > > > > ii) if CPUID reports that migration is supported, issue a wrmsrl() > > to enable the SEV live migration support > > > > - If EFI, > > > > i) check for the KVM_FEATURE_CPUID > > > > ii) If CPUID reports that migration is supported, read the UEFI variable which > > indicates OVMF support for live migration > > > > iii) the variable indicates live migration is supported, issue a wrmsrl() to > > enable the SEV live migration support > > > > The EFI live migration check is done using a late_initcall() callback. > > > > Also, ensure that _bss_decrypted section is marked as decrypted in the > > shared pages list. > > > > Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> > > --- > > arch/x86/include/asm/mem_encrypt.h | 8 +++++ > > arch/x86/kernel/kvm.c | 52 ++++++++++++++++++++++++++++++ > > arch/x86/mm/mem_encrypt.c | 41 +++++++++++++++++++++++ > > 3 files changed, 101 insertions(+) > > > > diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h > > index 31c4df123aa0..19b77f3a62dc 100644 > > --- a/arch/x86/include/asm/mem_encrypt.h > > +++ b/arch/x86/include/asm/mem_encrypt.h > > @@ -21,6 +21,7 @@ > > extern u64 sme_me_mask; > > extern u64 sev_status; > > extern bool sev_enabled; > > +extern bool sev_live_migration_enabled; > > > > void sme_encrypt_execute(unsigned long encrypted_kernel_vaddr, > > unsigned long decrypted_kernel_vaddr, > > @@ -44,8 +45,11 @@ void __init sme_enable(struct boot_params *bp); > > > > int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size); > > int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size); > > +void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages, > > + bool enc); > > > > void __init mem_encrypt_free_decrypted_mem(void); > > +void __init check_kvm_sev_migration(void); > > > > /* Architecture __weak replacement functions */ > > void __init mem_encrypt_init(void); > > @@ -60,6 +64,7 @@ bool sev_es_active(void); > > #else /* !CONFIG_AMD_MEM_ENCRYPT */ > > > > #define sme_me_mask 0ULL > > +#define sev_live_migration_enabled false > > > > static inline void __init sme_early_encrypt(resource_size_t paddr, > > unsigned long size) { } > > @@ -84,8 +89,11 @@ static inline int __init > > early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; } > > static inline int __init > > early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { return 0; } > > +static inline void __init > > +early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages, bool enc) {} > > > > static inline void mem_encrypt_free_decrypted_mem(void) { } > > +static inline void check_kvm_sev_migration(void) { } > > > > #define __bss_decrypted > > > > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c > > index 78bb0fae3982..bcc82e0c9779 100644 > > --- a/arch/x86/kernel/kvm.c > > +++ b/arch/x86/kernel/kvm.c > > @@ -26,6 +26,7 @@ > > #include <linux/kprobes.h> > > #include <linux/nmi.h> > > #include <linux/swait.h> > > +#include <linux/efi.h> > > #include <asm/timer.h> > > #include <asm/cpu.h> > > #include <asm/traps.h> > > @@ -429,6 +430,56 @@ static inline void __set_percpu_decrypted(void *ptr, unsigned long size) > > early_set_memory_decrypted((unsigned long) ptr, size); > > } > > > > +static int __init setup_kvm_sev_migration(void) > > +{ > > + efi_char16_t efi_sev_live_migration_enabled[] = L"SevLiveMigrationEnabled"; > > + efi_guid_t efi_variable_guid = MEM_ENCRYPT_GUID; > > + efi_status_t status; > > + unsigned long size; > > + bool enabled; > > + > > + /* > > + * check_kvm_sev_migration() invoked via kvm_init_platform() before > > + * this callback would have setup the indicator that live migration > > + * feature is supported/enabled. > > + */ > > + if (!sev_live_migration_enabled) > > + return 0; > > + > > + if (!efi_enabled(EFI_RUNTIME_SERVICES)) { > > + pr_info("%s : EFI runtime services are not enabled\n", __func__); > > + return 0; > > + } > > + > > + size = sizeof(enabled); > > + > > + /* Get variable contents into buffer */ > > + status = efi.get_variable(efi_sev_live_migration_enabled, > > + &efi_variable_guid, NULL, &size, &enabled); > > + > > + if (status == EFI_NOT_FOUND) { > > + pr_info("%s : EFI live migration variable not found\n", __func__); > > + return 0; > > + } > > + > > + if (status != EFI_SUCCESS) { > > + pr_info("%s : EFI variable retrieval failed\n", __func__); > > + return 0; > > + } > > + > > + if (enabled == 0) { > > + pr_info("%s: live migration disabled in EFI\n", __func__); > > + return 0; > > + } > > + > > + pr_info("%s : live migration enabled in EFI\n", __func__); > > + wrmsrl(MSR_KVM_SEV_LIVE_MIGRATION, KVM_SEV_LIVE_MIGRATION_ENABLED); > > + > > + return true; > > +} > > + > > +late_initcall(setup_kvm_sev_migration); > > + > > /* > > * Iterate through all possible CPUs and map the memory region pointed > > * by apf_reason, steal_time and kvm_apic_eoi as decrypted at once. > > @@ -747,6 +798,7 @@ static bool __init kvm_msi_ext_dest_id(void) > > > > static void __init kvm_init_platform(void) > > { > > + check_kvm_sev_migration(); > > kvmclock_init(); > > x86_platform.apic_post_init = kvm_apic_init; > > } > > diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c > > index fae9ccbd0da7..4de417333c09 100644 > > --- a/arch/x86/mm/mem_encrypt.c > > +++ b/arch/x86/mm/mem_encrypt.c > > @@ -20,6 +20,7 @@ > > #include <linux/bitops.h> > > #include <linux/dma-mapping.h> > > #include <linux/kvm_para.h> > > +#include <linux/efi.h> > > > > #include <asm/tlbflush.h> > > #include <asm/fixmap.h> > > @@ -48,6 +49,8 @@ EXPORT_SYMBOL_GPL(sev_enable_key); > > > > bool sev_enabled __section(".data"); > > > > +bool sev_live_migration_enabled __section(".data"); > > + > > /* Buffer used for early in-place encryption by BSP, no locking needed */ > > static char sme_early_buffer[PAGE_SIZE] __initdata __aligned(PAGE_SIZE); > > > > @@ -237,6 +240,9 @@ static void set_memory_enc_dec_hypercall(unsigned long vaddr, int npages, > > unsigned long sz = npages << PAGE_SHIFT; > > unsigned long vaddr_end, vaddr_next; > > > > + if (!sev_live_migration_enabled) > > + return; > > + > > vaddr_end = vaddr + sz; > > > > for (; vaddr < vaddr_end; vaddr = vaddr_next) { > > @@ -407,6 +413,12 @@ int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size) > > return early_set_memory_enc_dec(vaddr, size, true); > > } > > > > +void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages, > > + bool enc) > > +{ > > + set_memory_enc_dec_hypercall(vaddr, npages, enc); > > +} > > + > > /* > > * 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 > > @@ -462,6 +474,35 @@ bool force_dma_unencrypted(struct device *dev) > > return false; > > } > > > > +void __init check_kvm_sev_migration(void) > > +{ > > + if (sev_active() && > > + kvm_para_has_feature(KVM_FEATURE_SEV_LIVE_MIGRATION)) { > > + unsigned long nr_pages; > > + > > + pr_info("KVM enable live migration\n"); > > + sev_live_migration_enabled = true; > > + > > + /* > > + * Ensure that _bss_decrypted section is marked as decrypted in the > > + * shared pages list. > > + */ > > + nr_pages = DIV_ROUND_UP(__end_bss_decrypted - __start_bss_decrypted, > > + PAGE_SIZE); > > + early_set_mem_enc_dec_hypercall((unsigned long)__start_bss_decrypted, > > + nr_pages, 0); > > + > > + /* > > + * If not booted using EFI, enable Live migration support. > > + */ > > + if (!efi_enabled(EFI_BOOT)) > > + wrmsrl(MSR_KVM_SEV_LIVE_MIGRATION, > > + KVM_SEV_LIVE_MIGRATION_ENABLED); > > + } else { > > + pr_info("KVM enable live migration feature unsupported\n"); > I might be misunderstanding this, but I'm not sure this log message is > correct: isn't the intention that the late initcall will be the one to > check if this should be enabled later in this case? > Yes, you are right, this log message should be removed. > I have a similar question above about the log message after > "!efi_enabled(EFI_RUNTIME_SERVICES)": shouldn't that avoid logging if > !efi_enabled(EFI_BOOT) (since the wrmsl call already had been made > here?) Yes, probably that check can be additionally added. Thanks, Ashish > > + } > > +} > > + > > void __init mem_encrypt_free_decrypted_mem(void) > > { > > unsigned long vaddr, vaddr_end, npages; > > -- > > 2.17.1 > > > > Other than these: > Reviewed-by: Steve Rutherford <srutherford@google.com>
diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h index 31c4df123aa0..19b77f3a62dc 100644 --- a/arch/x86/include/asm/mem_encrypt.h +++ b/arch/x86/include/asm/mem_encrypt.h @@ -21,6 +21,7 @@ extern u64 sme_me_mask; extern u64 sev_status; extern bool sev_enabled; +extern bool sev_live_migration_enabled; void sme_encrypt_execute(unsigned long encrypted_kernel_vaddr, unsigned long decrypted_kernel_vaddr, @@ -44,8 +45,11 @@ void __init sme_enable(struct boot_params *bp); int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size); int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size); +void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages, + bool enc); void __init mem_encrypt_free_decrypted_mem(void); +void __init check_kvm_sev_migration(void); /* Architecture __weak replacement functions */ void __init mem_encrypt_init(void); @@ -60,6 +64,7 @@ bool sev_es_active(void); #else /* !CONFIG_AMD_MEM_ENCRYPT */ #define sme_me_mask 0ULL +#define sev_live_migration_enabled false static inline void __init sme_early_encrypt(resource_size_t paddr, unsigned long size) { } @@ -84,8 +89,11 @@ static inline int __init early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; } static inline int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { return 0; } +static inline void __init +early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages, bool enc) {} static inline void mem_encrypt_free_decrypted_mem(void) { } +static inline void check_kvm_sev_migration(void) { } #define __bss_decrypted diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 78bb0fae3982..bcc82e0c9779 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -26,6 +26,7 @@ #include <linux/kprobes.h> #include <linux/nmi.h> #include <linux/swait.h> +#include <linux/efi.h> #include <asm/timer.h> #include <asm/cpu.h> #include <asm/traps.h> @@ -429,6 +430,56 @@ static inline void __set_percpu_decrypted(void *ptr, unsigned long size) early_set_memory_decrypted((unsigned long) ptr, size); } +static int __init setup_kvm_sev_migration(void) +{ + efi_char16_t efi_sev_live_migration_enabled[] = L"SevLiveMigrationEnabled"; + efi_guid_t efi_variable_guid = MEM_ENCRYPT_GUID; + efi_status_t status; + unsigned long size; + bool enabled; + + /* + * check_kvm_sev_migration() invoked via kvm_init_platform() before + * this callback would have setup the indicator that live migration + * feature is supported/enabled. + */ + if (!sev_live_migration_enabled) + return 0; + + if (!efi_enabled(EFI_RUNTIME_SERVICES)) { + pr_info("%s : EFI runtime services are not enabled\n", __func__); + return 0; + } + + size = sizeof(enabled); + + /* Get variable contents into buffer */ + status = efi.get_variable(efi_sev_live_migration_enabled, + &efi_variable_guid, NULL, &size, &enabled); + + if (status == EFI_NOT_FOUND) { + pr_info("%s : EFI live migration variable not found\n", __func__); + return 0; + } + + if (status != EFI_SUCCESS) { + pr_info("%s : EFI variable retrieval failed\n", __func__); + return 0; + } + + if (enabled == 0) { + pr_info("%s: live migration disabled in EFI\n", __func__); + return 0; + } + + pr_info("%s : live migration enabled in EFI\n", __func__); + wrmsrl(MSR_KVM_SEV_LIVE_MIGRATION, KVM_SEV_LIVE_MIGRATION_ENABLED); + + return true; +} + +late_initcall(setup_kvm_sev_migration); + /* * Iterate through all possible CPUs and map the memory region pointed * by apf_reason, steal_time and kvm_apic_eoi as decrypted at once. @@ -747,6 +798,7 @@ static bool __init kvm_msi_ext_dest_id(void) static void __init kvm_init_platform(void) { + check_kvm_sev_migration(); kvmclock_init(); x86_platform.apic_post_init = kvm_apic_init; } diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index fae9ccbd0da7..4de417333c09 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -20,6 +20,7 @@ #include <linux/bitops.h> #include <linux/dma-mapping.h> #include <linux/kvm_para.h> +#include <linux/efi.h> #include <asm/tlbflush.h> #include <asm/fixmap.h> @@ -48,6 +49,8 @@ EXPORT_SYMBOL_GPL(sev_enable_key); bool sev_enabled __section(".data"); +bool sev_live_migration_enabled __section(".data"); + /* Buffer used for early in-place encryption by BSP, no locking needed */ static char sme_early_buffer[PAGE_SIZE] __initdata __aligned(PAGE_SIZE); @@ -237,6 +240,9 @@ static void set_memory_enc_dec_hypercall(unsigned long vaddr, int npages, unsigned long sz = npages << PAGE_SHIFT; unsigned long vaddr_end, vaddr_next; + if (!sev_live_migration_enabled) + return; + vaddr_end = vaddr + sz; for (; vaddr < vaddr_end; vaddr = vaddr_next) { @@ -407,6 +413,12 @@ int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size) return early_set_memory_enc_dec(vaddr, size, true); } +void __init early_set_mem_enc_dec_hypercall(unsigned long vaddr, int npages, + bool enc) +{ + set_memory_enc_dec_hypercall(vaddr, npages, enc); +} + /* * 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 @@ -462,6 +474,35 @@ bool force_dma_unencrypted(struct device *dev) return false; } +void __init check_kvm_sev_migration(void) +{ + if (sev_active() && + kvm_para_has_feature(KVM_FEATURE_SEV_LIVE_MIGRATION)) { + unsigned long nr_pages; + + pr_info("KVM enable live migration\n"); + sev_live_migration_enabled = true; + + /* + * Ensure that _bss_decrypted section is marked as decrypted in the + * shared pages list. + */ + nr_pages = DIV_ROUND_UP(__end_bss_decrypted - __start_bss_decrypted, + PAGE_SIZE); + early_set_mem_enc_dec_hypercall((unsigned long)__start_bss_decrypted, + nr_pages, 0); + + /* + * If not booted using EFI, enable Live migration support. + */ + if (!efi_enabled(EFI_BOOT)) + wrmsrl(MSR_KVM_SEV_LIVE_MIGRATION, + KVM_SEV_LIVE_MIGRATION_ENABLED); + } else { + pr_info("KVM enable live migration feature unsupported\n"); + } +} + void __init mem_encrypt_free_decrypted_mem(void) { unsigned long vaddr, vaddr_end, npages;