From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: kvm@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org,
Sean Christopherson <seanjc@google.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>,
Maxim Levitsky <mlevitsk@redhat.com>
Subject: [PATCH 2/7] KVM: nVMX: Release enlightened VMCS on VMCLEAR
Date: Tue, 11 May 2021 13:19:51 +0200 [thread overview]
Message-ID: <20210511111956.1555830-3-vkuznets@redhat.com> (raw)
In-Reply-To: <20210511111956.1555830-1-vkuznets@redhat.com>
Unlike VMREAD/VMWRITE/VMPTRLD, VMCLEAR is a valid instruction when
enlightened VMCS is in use. TLFS has the following brief description:
"The L1 hypervisor can execute a VMCLEAR instruction to transition an
enlightened VMCS from the active to the non-active state". Normally,
this change can be ignored as unmapping active eVMCS can be postponed
until the next VMLAUNCH instruction but in case nested state is migrated
with KVM_GET_NESTED_STATE/KVM_SET_NESTED_STATE, keeping eVMCS mapped
may result in its synchronization with VMCS12 and this is incorrect:
L1 hypervisor is free to reuse inactive eVMCS memory for something else.
Inactive eVMCS after VMCLEAR can just be unmapped.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/vmx/nested.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 3080e00c8f90..ea2869d8b823 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5008,6 +5008,8 @@ static int handle_vmclear(struct kvm_vcpu *vcpu)
vmptr + offsetof(struct vmcs12,
launch_state),
&zero, sizeof(zero));
+ } else if (vmx->nested.hv_evmcs && vmptr == vmx->nested.hv_evmcs_vmptr) {
+ nested_release_evmcs(vcpu);
}
return nested_vmx_succeed(vcpu);
--
2.30.2
next prev parent reply other threads:[~2021-05-11 11:20 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-11 11:19 [PATCH 0/7] KVM: nVMX: Fixes for nested state migration when eVMCS is in use Vitaly Kuznetsov
2021-05-11 11:19 ` [PATCH 1/7] KVM: nVMX: Introduce nested_evmcs_is_used() Vitaly Kuznetsov
2021-05-11 11:19 ` Vitaly Kuznetsov [this message]
2021-05-11 11:19 ` [PATCH 3/7] KVM: nVMX: Ignore 'hv_clean_fields' data when eVMCS data is copied in vmx_get_nested_state() Vitaly Kuznetsov
2021-05-11 16:37 ` Sean Christopherson
2021-05-12 7:14 ` Vitaly Kuznetsov
2021-05-11 11:19 ` [PATCH 4/7] KVM: nVMX: Force enlightened VMCS sync from nested_vmx_failValid() Vitaly Kuznetsov
2021-05-11 11:19 ` [PATCH 5/7] KVM: nVMX: Reset eVMCS clean fields data from prepare_vmcs02() Vitaly Kuznetsov
2021-05-11 16:32 ` Sean Christopherson
2021-05-12 7:19 ` Vitaly Kuznetsov
2021-05-11 11:19 ` [PATCH 6/7] KVM: nVMX: Request to sync eVMCS from VMCS12 after migration Vitaly Kuznetsov
2021-05-11 11:19 ` [PATCH 7/7] KVM: selftests: evmcs_test: Test that KVM_STATE_NESTED_EVMCS is never lost Vitaly Kuznetsov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210511111956.1555830-3-vkuznets@redhat.com \
--to=vkuznets@redhat.com \
--cc=jmattson@google.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mlevitsk@redhat.com \
--cc=pbonzini@redhat.com \
--cc=seanjc@google.com \
--cc=wanpengli@tencent.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).