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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 03/11] KVM: nVMX: Release eVMCS when enlightened VMENTRY was disabled
Date: Wed, 26 May 2021 15:20:18 +0200	[thread overview]
Message-ID: <20210526132026.270394-4-vkuznets@redhat.com> (raw)
In-Reply-To: <20210526132026.270394-1-vkuznets@redhat.com>

In theory, L1 can try to disable enlightened VMENTRY in VP assist page and
try to issue VMLAUNCH/VMRESUME. While nested_vmx_handle_enlightened_vmptrld()
properly handles this as 'EVMPTRLD_DISABLED', previously mapped eVMCS
remains mapped and thus all evmptr_is_valid() checks will still pass and
nested_vmx_run() will proceed when it shouldn't.

Release eVMCS immediately when we detect that enlightened vmentry was
disabled by L1.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/kvm/vmx/nested.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index c662278e4793..ea2c52aad8f0 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1980,8 +1980,10 @@ static enum nested_evmptrld_status nested_vmx_handle_enlightened_vmptrld(
 	if (likely(!vmx->nested.enlightened_vmcs_enabled))
 		return EVMPTRLD_DISABLED;
 
-	if (!nested_enlightened_vmentry(vcpu, &evmcs_gpa))
+	if (!nested_enlightened_vmentry(vcpu, &evmcs_gpa)) {
+		nested_release_evmcs(vcpu);
 		return EVMPTRLD_DISABLED;
+	}
 
 	if (unlikely(evmcs_gpa != vmx->nested.hv_evmcs_vmptr)) {
 		vmx->nested.current_vmptr = -1ull;
-- 
2.31.1


  parent reply	other threads:[~2021-05-26 13:21 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 ` Vitaly Kuznetsov [this message]
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 ` [PATCH v3 07/11] KVM: nVMX: Ignore 'hv_clean_fields' data when eVMCS data is copied in vmx_get_nested_state() Vitaly Kuznetsov
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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