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From: Ashish Kalra <Ashish.Kalra@amd.com>
To: pbonzini@redhat.com
Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com,
	joro@8bytes.org, bp@suse.de, thomas.lendacky@amd.com,
	x86@kernel.org, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org, srutherford@google.com,
	seanjc@google.com, venu.busireddy@oracle.com,
	brijesh.singh@amd.com
Subject: [PATCH v11 10/13] KVM: x86: Introduce new KVM_FEATURE_SEV_LIVE_MIGRATION feature & Custom MSR.
Date: Mon,  5 Apr 2021 14:30:09 +0000	[thread overview]
Message-ID: <69dd6d5c4f467e6c8a0f4f1065f7f2a3d25f37f8.1617302792.git.ashish.kalra@amd.com> (raw)
In-Reply-To: <cover.1617302792.git.ashish.kalra@amd.com>

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_MIGRATION for guest to enable the SEV live migration
feature.

MSR is handled by userspace using MSR filters.

Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
---
 Documentation/virt/kvm/cpuid.rst     |  5 +++++
 Documentation/virt/kvm/msr.rst       | 12 ++++++++++++
 arch/x86/include/uapi/asm/kvm_para.h |  4 ++++
 arch/x86/kvm/cpuid.c                 |  3 ++-
 arch/x86/kvm/svm/svm.c               | 22 ++++++++++++++++++++++
 5 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/Documentation/virt/kvm/cpuid.rst b/Documentation/virt/kvm/cpuid.rst
index cf62162d4be2..0bdb6cdb12d3 100644
--- a/Documentation/virt/kvm/cpuid.rst
+++ b/Documentation/virt/kvm/cpuid.rst
@@ -96,6 +96,11 @@ KVM_FEATURE_MSI_EXT_DEST_ID        15          guest checks this feature bit
                                                before using extended destination
                                                ID bits in MSI address bits 11-5.
 
+KVM_FEATURE_SEV_LIVE_MIGRATION     16          guest checks this feature bit before
+                                               using the page encryption state
+                                               hypercall to notify the page state
+                                               change
+
 KVM_FEATURE_CLOCKSOURCE_STABLE_BIT 24          host will warn if no guest-side
                                                per-cpu warps are expected in
                                                kvmclock
diff --git a/Documentation/virt/kvm/msr.rst b/Documentation/virt/kvm/msr.rst
index e37a14c323d2..020245d16087 100644
--- a/Documentation/virt/kvm/msr.rst
+++ b/Documentation/virt/kvm/msr.rst
@@ -376,3 +376,15 @@ data:
 	write '1' to bit 0 of the MSR, this causes the host to re-scan its queue
 	and check if there are more notifications pending. The MSR is available
 	if KVM_FEATURE_ASYNC_PF_INT is present in CPUID.
+
+MSR_KVM_SEV_LIVE_MIGRATION:
+        0x4b564d08
+
+	Control SEV Live Migration features.
+
+data:
+        Bit 0 enables (1) or disables (0) host-side SEV Live Migration feature,
+        in other words, this is guest->host communication that it's properly
+        handling the shared pages list.
+
+        All other bits are reserved.
diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
index 950afebfba88..f6bfa138874f 100644
--- a/arch/x86/include/uapi/asm/kvm_para.h
+++ b/arch/x86/include/uapi/asm/kvm_para.h
@@ -33,6 +33,7 @@
 #define KVM_FEATURE_PV_SCHED_YIELD	13
 #define KVM_FEATURE_ASYNC_PF_INT	14
 #define KVM_FEATURE_MSI_EXT_DEST_ID	15
+#define KVM_FEATURE_SEV_LIVE_MIGRATION	16
 
 #define KVM_HINTS_REALTIME      0
 
@@ -54,6 +55,7 @@
 #define MSR_KVM_POLL_CONTROL	0x4b564d05
 #define MSR_KVM_ASYNC_PF_INT	0x4b564d06
 #define MSR_KVM_ASYNC_PF_ACK	0x4b564d07
+#define MSR_KVM_SEV_LIVE_MIGRATION	0x4b564d08
 
 struct kvm_steal_time {
 	__u64 steal;
@@ -136,4 +138,6 @@ 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 BIT_ULL(0)
+
 #endif /* _UAPI_ASM_X86_KVM_PARA_H */
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 6bd2f8b830e4..4e2e69a692aa 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -812,7 +812,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 			     (1 << KVM_FEATURE_PV_SEND_IPI) |
 			     (1 << KVM_FEATURE_POLL_CONTROL) |
 			     (1 << KVM_FEATURE_PV_SCHED_YIELD) |
-			     (1 << KVM_FEATURE_ASYNC_PF_INT);
+			     (1 << KVM_FEATURE_ASYNC_PF_INT) |
+			     (1 << KVM_FEATURE_SEV_LIVE_MIGRATION);
 
 		if (sched_info_on())
 			entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 3cbf000beff1..1ac79e2f2a6c 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2800,6 +2800,17 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	case MSR_F10H_DECFG:
 		msr_info->data = svm->msr_decfg;
 		break;
+	case MSR_KVM_SEV_LIVE_MIGRATION:
+		if (!sev_guest(vcpu->kvm))
+			return 1;
+
+		if (!guest_cpuid_has(vcpu, KVM_FEATURE_SEV_LIVE_MIGRATION))
+			return 1;
+
+		/*
+		 * Let userspace handle the MSR using MSR filters.
+		 */
+		return KVM_MSR_RET_FILTERED;
 	default:
 		return kvm_get_msr_common(vcpu, msr_info);
 	}
@@ -2996,6 +3007,17 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
 		svm->msr_decfg = data;
 		break;
 	}
+	case MSR_KVM_SEV_LIVE_MIGRATION:
+		if (!sev_guest(vcpu->kvm))
+			return 1;
+
+		if (!guest_cpuid_has(vcpu, KVM_FEATURE_SEV_LIVE_MIGRATION))
+			return 1;
+
+		/*
+		 * Let userspace handle the MSR using MSR filters.
+		 */
+		return KVM_MSR_RET_FILTERED;
 	case MSR_IA32_APICBASE:
 		if (kvm_vcpu_apicv_active(vcpu))
 			avic_update_vapic_bar(to_svm(vcpu), data);
-- 
2.17.1


  parent reply	other threads:[~2021-04-05 14:30 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-05 14:20 [PATCH v11 00/13] Add AMD SEV guest live migration support Ashish Kalra
2021-04-05 14:21 ` [PATCH v11 01/13] KVM: SVM: Add KVM_SEV SEND_START command Ashish Kalra
2021-04-05 14:23 ` [PATCH v11 02/13] KVM: SVM: Add KVM_SEND_UPDATE_DATA command Ashish Kalra
2021-04-05 14:23 ` [PATCH v11 03/13] KVM: SVM: Add KVM_SEV_SEND_FINISH command Ashish Kalra
2021-04-05 14:24 ` [PATCH v11 04/13] KVM: SVM: Add support for KVM_SEV_RECEIVE_START command Ashish Kalra
2021-04-05 14:24 ` [PATCH v11 05/13] KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command Ashish Kalra
2021-04-05 14:25 ` [PATCH v11 06/13] KVM: SVM: Add KVM_SEV_RECEIVE_FINISH command Ashish Kalra
2021-04-05 14:26 ` [PATCH v11 07/13] KVM: x86: Add AMD SEV specific Hypercall3 Ashish Kalra
2021-04-05 14:28 ` [PATCH v11 08/13] KVM: X86: Introduce KVM_HC_PAGE_ENC_STATUS hypercall Ashish Kalra
2021-04-05 20:42   ` Steve Rutherford
2021-04-06  6:22     ` Ashish Kalra
2021-04-06 15:11       ` Sean Christopherson
2021-04-06 15:20         ` Sean Christopherson
2021-04-06 18:14       ` Ashish Kalra
2021-04-06 15:48   ` Sean Christopherson
2021-04-06 16:07     ` Ashish Kalra
2021-04-06 20:14       ` Steve Rutherford
2021-04-06 20:27         ` Sean Christopherson
2021-04-07 14:01     ` Ashish Kalra
2021-04-05 14:29 ` [PATCH v11 09/13] mm: x86: Invoke hypercall when page encryption status is changed Ashish Kalra
2021-04-05 14:30 ` Ashish Kalra [this message]
2021-04-06  1:39   ` [PATCH v11 10/13] KVM: x86: Introduce new KVM_FEATURE_SEV_LIVE_MIGRATION feature & Custom MSR Steve Rutherford
2021-04-06 13:26     ` Ashish Kalra
2021-04-06 13:47       ` Paolo Bonzini
2021-04-06 13:59         ` Ashish Kalra
2021-04-06 19:41           ` Steve Rutherford
2021-04-05 14:30 ` [PATCH v11 11/13] EFI: Introduce the new AMD Memory Encryption GUID Ashish Kalra
2021-04-05 14:31 ` [PATCH v11 12/13] x86/kvm: Add guest support for detecting and enabling SEV Live Migration feature Ashish Kalra
2021-04-05 14:35 ` [PATCH v11 13/13] x86/kvm: Add kexec support for SEV Live Migration Ashish Kalra
2021-04-05 15:17 ` [PATCH v11 00/13] Add AMD SEV guest live migration support Peter Gonda
2021-04-05 18:27   ` Steve Rutherford
2021-04-06 13:48     ` Paolo Bonzini
2021-04-06  1:43 ` Steve Rutherford

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