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From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: kvm@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>,
	Maxim Levitsky <mlevitsk@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH v3 07/11] KVM: nVMX: Ignore 'hv_clean_fields' data when eVMCS data is copied in vmx_get_nested_state()
Date: Wed, 26 May 2021 15:20:22 +0200	[thread overview]
Message-ID: <20210526132026.270394-8-vkuznets@redhat.com> (raw)
In-Reply-To: <20210526132026.270394-1-vkuznets@redhat.com>

'Clean fields' data from enlightened VMCS is only valid upon vmentry: L1
hypervisor is not obliged to keep it up-to-date while it is mangling L2's
state, KVM_GET_NESTED_STATE request may come at a wrong moment when actual
eVMCS changes are unsynchronized with 'hv_clean_fields'. As upon migration
VMCS12 is used as a source of ultimate truth, we must make sure we pick all
the changes to eVMCS and thus 'clean fields' data must be ignored.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/kvm/vmx/nested.c | 43 +++++++++++++++++++++++----------------
 1 file changed, 25 insertions(+), 18 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 080990ebe989..93ef8e00828e 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1587,7 +1587,7 @@ static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx)
 	vmcs_load(vmx->loaded_vmcs->vmcs);
 }
 
-static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx)
+static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx, u32 hv_clean_fields)
 {
 	struct vmcs12 *vmcs12 = vmx->nested.cached_vmcs12;
 	struct hv_enlightened_vmcs *evmcs = vmx->nested.hv_evmcs;
@@ -1596,7 +1596,7 @@ static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx)
 	vmcs12->tpr_threshold = evmcs->tpr_threshold;
 	vmcs12->guest_rip = evmcs->guest_rip;
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_BASIC))) {
 		vmcs12->guest_rsp = evmcs->guest_rsp;
 		vmcs12->guest_rflags = evmcs->guest_rflags;
@@ -1604,23 +1604,23 @@ static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx)
 			evmcs->guest_interruptibility_info;
 	}
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_PROC))) {
 		vmcs12->cpu_based_vm_exec_control =
 			evmcs->cpu_based_vm_exec_control;
 	}
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_EXCPN))) {
 		vmcs12->exception_bitmap = evmcs->exception_bitmap;
 	}
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_ENTRY))) {
 		vmcs12->vm_entry_controls = evmcs->vm_entry_controls;
 	}
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_EVENT))) {
 		vmcs12->vm_entry_intr_info_field =
 			evmcs->vm_entry_intr_info_field;
@@ -1630,7 +1630,7 @@ static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx)
 			evmcs->vm_entry_instruction_len;
 	}
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_GRP1))) {
 		vmcs12->host_ia32_pat = evmcs->host_ia32_pat;
 		vmcs12->host_ia32_efer = evmcs->host_ia32_efer;
@@ -1650,7 +1650,7 @@ static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx)
 		vmcs12->host_tr_selector = evmcs->host_tr_selector;
 	}
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_GRP1))) {
 		vmcs12->pin_based_vm_exec_control =
 			evmcs->pin_based_vm_exec_control;
@@ -1659,18 +1659,18 @@ static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx)
 			evmcs->secondary_vm_exec_control;
 	}
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_IO_BITMAP))) {
 		vmcs12->io_bitmap_a = evmcs->io_bitmap_a;
 		vmcs12->io_bitmap_b = evmcs->io_bitmap_b;
 	}
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP))) {
 		vmcs12->msr_bitmap = evmcs->msr_bitmap;
 	}
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP2))) {
 		vmcs12->guest_es_base = evmcs->guest_es_base;
 		vmcs12->guest_cs_base = evmcs->guest_cs_base;
@@ -1710,14 +1710,14 @@ static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx)
 		vmcs12->guest_tr_selector = evmcs->guest_tr_selector;
 	}
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_GRP2))) {
 		vmcs12->tsc_offset = evmcs->tsc_offset;
 		vmcs12->virtual_apic_page_addr = evmcs->virtual_apic_page_addr;
 		vmcs12->xss_exit_bitmap = evmcs->xss_exit_bitmap;
 	}
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CRDR))) {
 		vmcs12->cr0_guest_host_mask = evmcs->cr0_guest_host_mask;
 		vmcs12->cr4_guest_host_mask = evmcs->cr4_guest_host_mask;
@@ -1729,7 +1729,7 @@ static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx)
 		vmcs12->guest_dr7 = evmcs->guest_dr7;
 	}
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_POINTER))) {
 		vmcs12->host_fs_base = evmcs->host_fs_base;
 		vmcs12->host_gs_base = evmcs->host_gs_base;
@@ -1739,13 +1739,13 @@ static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx)
 		vmcs12->host_rsp = evmcs->host_rsp;
 	}
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_XLAT))) {
 		vmcs12->ept_pointer = evmcs->ept_pointer;
 		vmcs12->virtual_processor_id = evmcs->virtual_processor_id;
 	}
 
-	if (unlikely(!(evmcs->hv_clean_fields &
+	if (unlikely(!(hv_clean_fields &
 		       HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1))) {
 		vmcs12->vmcs_link_pointer = evmcs->vmcs_link_pointer;
 		vmcs12->guest_ia32_debugctl = evmcs->guest_ia32_debugctl;
@@ -3483,7 +3483,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
 		return nested_vmx_failInvalid(vcpu);
 
 	if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
-		copy_enlightened_to_vmcs12(vmx);
+		copy_enlightened_to_vmcs12(vmx, vmx->nested.hv_evmcs->hv_clean_fields);
 		/* Enlightened VMCS doesn't have launch state */
 		vmcs12->launch_state = !launch;
 	} else if (enable_shadow_vmcs) {
@@ -6118,7 +6118,14 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu,
 		copy_vmcs02_to_vmcs12_rare(vcpu, get_vmcs12(vcpu));
 		if (!vmx->nested.need_vmcs12_to_shadow_sync) {
 			if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
-				copy_enlightened_to_vmcs12(vmx);
+				/*
+				 * L1 hypervisor is not obliged to keep eVMCS
+				 * clean fields data always up-to-date while
+				 * not in guest mode, 'hv_clean_fields' is only
+				 * supposed to be actual upon vmentry so we need
+				 * to ignore it here and do full copy.
+				 */
+				copy_enlightened_to_vmcs12(vmx, 0);
 			else if (enable_shadow_vmcs)
 				copy_shadow_to_vmcs12(vmx);
 		}
-- 
2.31.1


  parent reply	other threads:[~2021-05-26 13:22 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-26 13:20 [PATCH v3 00/11] KVM: nVMX: Fixes for nested state migration when eVMCS is in use Vitaly Kuznetsov
2021-05-26 13:20 ` [PATCH v3 01/11] KVM: nVMX: Use '-1' in 'hv_evmcs_vmptr' to indicate that eVMCS is not " Vitaly Kuznetsov
2021-05-26 13:20 ` [PATCH v3 02/11] KVM: nVMX: Don't set 'dirty_vmcs12' flag on enlightened VMPTRLD Vitaly Kuznetsov
2021-05-26 13:20 ` [PATCH v3 03/11] KVM: nVMX: Release eVMCS when enlightened VMENTRY was disabled Vitaly Kuznetsov
2021-05-26 13:20 ` [PATCH v3 04/11] KVM: nVMX: Make copy_vmcs12_to_enlightened()/copy_enlightened_to_vmcs12() return 'void' Vitaly Kuznetsov
2021-05-26 13:20 ` [PATCH v3 05/11] KVM: nVMX: Introduce 'EVMPTR_MAP_PENDING' post-migration state Vitaly Kuznetsov
2021-05-26 13:20 ` [PATCH v3 06/11] KVM: nVMX: Release enlightened VMCS on VMCLEAR Vitaly Kuznetsov
2021-05-26 13:20 ` Vitaly Kuznetsov [this message]
2021-05-26 13:20 ` [PATCH v3 08/11] KVM: nVMX: Force enlightened VMCS sync from nested_vmx_failValid() Vitaly Kuznetsov
2021-05-26 13:20 ` [PATCH v3 09/11] KVM: nVMX: Reset eVMCS clean fields data from prepare_vmcs02() Vitaly Kuznetsov
2021-05-26 13:20 ` [PATCH v3 10/11] KVM: nVMX: Request to sync eVMCS from VMCS12 after migration Vitaly Kuznetsov
2021-05-26 13:20 ` [PATCH v3 11/11] KVM: selftests: evmcs_test: Test that KVM_STATE_NESTED_EVMCS is never lost Vitaly Kuznetsov
2021-06-10 14:29 ` [PATCH v3 00/11] KVM: nVMX: Fixes for nested state migration when eVMCS is in use Vitaly Kuznetsov
2021-06-10 15:31   ` Paolo Bonzini

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