Messages in this thread | | | Subject | Re: [PATCH v6 13/14] KVM: x86: Introduce new KVM_FEATURE_SEV_LIVE_MIGRATION feature & Custom MSR. | From | Krish Sadhukhan <> | Date | Fri, 3 Apr 2020 16:46:30 -0700 |
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On 3/29/20 11:23 PM, Ashish Kalra wrote: > From: Ashish Kalra <ashish.kalra@amd.com> > > Add new KVM_FEATURE_SEV_LIVE_MIGRATION feature for guest to check > for host-side support for SEV live migration. Also add a new custom > MSR_KVM_SEV_LIVE_MIG_EN for guest to enable the SEV live migration > feature. > > Also, ensure that _bss_decrypted section is marked as decrypted in the > page encryption bitmap. > > Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> > --- > Documentation/virt/kvm/cpuid.rst | 4 ++++ > Documentation/virt/kvm/msr.rst | 10 ++++++++++ > arch/x86/include/asm/kvm_host.h | 3 +++ > arch/x86/include/uapi/asm/kvm_para.h | 5 +++++ > arch/x86/kernel/kvm.c | 4 ++++ > arch/x86/kvm/cpuid.c | 3 ++- > arch/x86/kvm/svm.c | 5 +++++ > arch/x86/kvm/x86.c | 7 +++++++ > arch/x86/mm/mem_encrypt.c | 14 +++++++++++++- > 9 files changed, 53 insertions(+), 2 deletions(-) > > diff --git a/Documentation/virt/kvm/cpuid.rst b/Documentation/virt/kvm/cpuid.rst > index 01b081f6e7ea..fcb191bb3016 100644 > --- a/Documentation/virt/kvm/cpuid.rst > +++ b/Documentation/virt/kvm/cpuid.rst > @@ -86,6 +86,10 @@ KVM_FEATURE_PV_SCHED_YIELD 13 guest checks this feature bit > before using paravirtualized > sched yield. > > +KVM_FEATURE_SEV_LIVE_MIGRATION 14 guest checks this feature bit > + before enabling SEV live > + migration feature. > + > KVM_FEATURE_CLOCSOURCE_STABLE_BIT 24 host will warn if no guest-side > per-cpu warps are expeced in > kvmclock > diff --git a/Documentation/virt/kvm/msr.rst b/Documentation/virt/kvm/msr.rst > index 33892036672d..7cd7786bbb03 100644 > --- a/Documentation/virt/kvm/msr.rst > +++ b/Documentation/virt/kvm/msr.rst > @@ -319,3 +319,13 @@ data: > > KVM guests can request the host not to poll on HLT, for example if > they are performing polling themselves. > + > +MSR_KVM_SEV_LIVE_MIG_EN: > + 0x4b564d06 > + > + Control SEV Live Migration features. > + > +data: > + Bit 0 enables (1) or disables (0) host-side SEV Live Migration feature. > + Bit 1 enables (1) or disables (0) support for SEV Live Migration extensions. > + All other bits are reserved. > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index a96ef6338cd2..ad5faaed43c0 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -780,6 +780,9 @@ struct kvm_vcpu_arch { > > u64 msr_kvm_poll_control; > > + /* SEV Live Migration MSR (AMD only) */ > + u64 msr_kvm_sev_live_migration_flag; > + > /* > * Indicates the guest is trying to write a gfn that contains one or > * more of the PTEs used to translate the write itself, i.e. the access > diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h > index 2a8e0b6b9805..d9d4953b42ad 100644 > --- a/arch/x86/include/uapi/asm/kvm_para.h > +++ b/arch/x86/include/uapi/asm/kvm_para.h > @@ -31,6 +31,7 @@ > #define KVM_FEATURE_PV_SEND_IPI 11 > #define KVM_FEATURE_POLL_CONTROL 12 > #define KVM_FEATURE_PV_SCHED_YIELD 13 > +#define KVM_FEATURE_SEV_LIVE_MIGRATION 14 > > #define KVM_HINTS_REALTIME 0 > > @@ -50,6 +51,7 @@ > #define MSR_KVM_STEAL_TIME 0x4b564d03 > #define MSR_KVM_PV_EOI_EN 0x4b564d04 > #define MSR_KVM_POLL_CONTROL 0x4b564d05 > +#define MSR_KVM_SEV_LIVE_MIG_EN 0x4b564d06 > > struct kvm_steal_time { > __u64 steal; > @@ -122,4 +124,7 @@ struct kvm_vcpu_pv_apf_data { > #define KVM_PV_EOI_ENABLED KVM_PV_EOI_MASK > #define KVM_PV_EOI_DISABLED 0x0 > > +#define KVM_SEV_LIVE_MIGRATION_ENABLED (1 << 0) > +#define KVM_SEV_LIVE_MIGRATION_EXTENSIONS_SUPPORTED (1 << 1) > + > #endif /* _UAPI_ASM_X86_KVM_PARA_H */ > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c > index 6efe0410fb72..8fcee0b45231 100644 > --- a/arch/x86/kernel/kvm.c > +++ b/arch/x86/kernel/kvm.c > @@ -418,6 +418,10 @@ static void __init sev_map_percpu_data(void) > if (!sev_active()) > return; > > + if (kvm_para_has_feature(KVM_FEATURE_SEV_LIVE_MIGRATION)) { > + wrmsrl(MSR_KVM_SEV_LIVE_MIG_EN, KVM_SEV_LIVE_MIGRATION_ENABLED); > + } > + > for_each_possible_cpu(cpu) { > __set_percpu_decrypted(&per_cpu(apf_reason, cpu), sizeof(apf_reason)); > __set_percpu_decrypted(&per_cpu(steal_time, cpu), sizeof(steal_time)); > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index b1c469446b07..74c8b2a7270c 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -716,7 +716,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, > (1 << KVM_FEATURE_ASYNC_PF_VMEXIT) | > (1 << KVM_FEATURE_PV_SEND_IPI) | > (1 << KVM_FEATURE_POLL_CONTROL) | > - (1 << KVM_FEATURE_PV_SCHED_YIELD); > + (1 << KVM_FEATURE_PV_SCHED_YIELD) | > + (1 << KVM_FEATURE_SEV_LIVE_MIGRATION); > > if (sched_info_on()) > entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index c99b0207a443..60ddc242a133 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -7632,6 +7632,7 @@ static int svm_page_enc_status_hc(struct kvm *kvm, unsigned long gpa, > unsigned long npages, unsigned long enc) > { > struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; > + struct kvm_vcpu *vcpu = kvm->vcpus[0]; > kvm_pfn_t pfn_start, pfn_end; > gfn_t gfn_start, gfn_end; > int ret; > @@ -7639,6 +7640,10 @@ static int svm_page_enc_status_hc(struct kvm *kvm, unsigned long gpa, > if (!sev_guest(kvm)) > return -EINVAL; > > + if (!(vcpu->arch.msr_kvm_sev_live_migration_flag & > + KVM_SEV_LIVE_MIGRATION_ENABLED)) > + return -ENOTTY; > + > if (!npages) > return 0; > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 2127ed937f53..82867b8798f8 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -2880,6 +2880,10 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > vcpu->arch.msr_kvm_poll_control = data; > break; > > + case MSR_KVM_SEV_LIVE_MIG_EN: > + vcpu->arch.msr_kvm_sev_live_migration_flag = data; > + break; > + > case MSR_IA32_MCG_CTL: > case MSR_IA32_MCG_STATUS: > case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1: > @@ -3126,6 +3130,9 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > case MSR_KVM_POLL_CONTROL: > msr_info->data = vcpu->arch.msr_kvm_poll_control; > break; > + case MSR_KVM_SEV_LIVE_MIG_EN: > + msr_info->data = vcpu->arch.msr_kvm_sev_live_migration_flag; > + break; > case MSR_IA32_P5_MC_ADDR: > case MSR_IA32_P5_MC_TYPE: > case MSR_IA32_MCG_CAP: > diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c > index c9800fa811f6..f6a841494845 100644 > --- a/arch/x86/mm/mem_encrypt.c > +++ b/arch/x86/mm/mem_encrypt.c > @@ -502,8 +502,20 @@ void __init mem_encrypt_init(void) > * With SEV, we need to make a hypercall when page encryption state is > * changed. > */ > - if (sev_active()) > + if (sev_active()) { > + unsigned long nr_pages; > + > pv_ops.mmu.page_encryption_changed = set_memory_enc_dec_hypercall; > + > + /* > + * Ensure that _bss_decrypted section is marked as decrypted in the > + * page encryption bitmap. > + */ > + nr_pages = DIV_ROUND_UP(__end_bss_decrypted - __start_bss_decrypted, > + PAGE_SIZE); > + set_memory_enc_dec_hypercall((unsigned long)__start_bss_decrypted, > + nr_pages, 0); > + } > #endif > > pr_info("AMD %s active\n", Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
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