From: Paolo Bonzini <pbonzini@redhat.com>
To: Jim Mattson <jmattson@google.com>,
Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Chenyi Qiang <chenyi.qiang@intel.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Joerg Roedel <joro@8bytes.org>, Xiaoyao Li <xiaoyao.li@intel.com>,
kvm list <kvm@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 3/5] KVM: nVMX: Update VMX controls MSR according to guest CPUID after setting VMX MSRs
Date: Fri, 11 Sep 2020 19:09:27 +0200 [thread overview]
Message-ID: <48fd0fd9-97b4-471e-d8e8-628f51dcdeff@redhat.com> (raw)
In-Reply-To: <CALMp9eSv3SrsJigB6KQg+dyS9GmYYCbC5v6QCx3f09951VZidA@mail.gmail.com>
On 02/09/20 20:32, Jim Mattson wrote:
>
> /* If not VM_EXIT_CLEAR_BNDCFGS, the L2 value propagates to L1. */
> if (vmcs12->vm_exit_controls & VM_EXIT_CLEAR_BNDCFGS)
> vmcs_write64(GUEST_BNDCFGS, 0);
>
> BTW, where does the L2 value propagate to L1 if not VM_EXIT_CLEAR_BNDCFGS?
Hmm, nowhere. :/ Probably something like this (not really thought through):
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 1e903d51912b..aba76aa99465 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -3317,7 +3317,8 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu,
if (!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS))
vmx->nested.vmcs01_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL);
if (kvm_mpx_supported() &&
- !(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS))
+ (!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS) ||
+ !(vmcs12->vm_exit_controls & VM_EXIT_CLEAR_BNDCFGS)))
vmx->nested.vmcs01_guest_bndcfgs = vmcs_read64(GUEST_BNDCFGS);
/*
@@ -4186,9 +4187,12 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
vmcs_write32(GUEST_IDTR_LIMIT, 0xFFFF);
vmcs_write32(GUEST_GDTR_LIMIT, 0xFFFF);
- /* If not VM_EXIT_CLEAR_BNDCFGS, the L2 value propagates to L1. */
- if (vmcs12->vm_exit_controls & VM_EXIT_CLEAR_BNDCFGS)
- vmcs_write64(GUEST_BNDCFGS, 0);
+ if (kvm_mpx_supported()) {
+ if (vmcs12->vm_exit_controls & VM_EXIT_CLEAR_BNDCFGS)
+ vmcs_write64(GUEST_BNDCFGS, 0);
+ else
+ vmcs_write64(GUEST_BNDCFGS, vmx->nested.vmcs01_guest_bndcfgs);
+ }
if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PAT) {
vmcs_write64(GUEST_IA32_PAT, vmcs12->host_ia32_pat);
@@ -4466,6 +4470,10 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
vmx_set_virtual_apic_mode(vcpu);
}
+ /* If not VM_EXIT_CLEAR_BNDCFGS, the L2 value propagates to L1. */
+ if (!(vmcs12->vm_exit_controls & VM_EXIT_CLEAR_BNDCFGS))
+ vmx->nested.vmcs01_guest_bndcfgs = vmcs12->guest_bndcfgs;
+
/* Unpin physical memory we referred to in vmcs02 */
if (vmx->nested.apic_access_page) {
kvm_release_page_clean(vmx->nested.apic_access_page);
which will also work in the failed vmentry case.
Paolo
next prev parent reply other threads:[~2020-09-11 17:10 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-28 8:56 [PATCH 0/5] Fix nested VMX controls MSRs Chenyi Qiang
2020-08-28 8:56 ` [PATCH 1/5] KVM: nVMX: Fix VMX controls MSRs setup when nested VMX enabled Chenyi Qiang
2020-08-28 17:43 ` Jim Mattson
2020-08-29 1:49 ` Chenyi Qiang
2020-08-29 2:51 ` Xiaoyao Li
2020-08-31 17:36 ` Jim Mattson
2020-09-01 3:27 ` Xiaoyao Li
2020-08-28 8:56 ` [PATCH 2/5] KVM: nVMX: Verify the VMX controls MSRs with the global capability when setting VMX MSRs Chenyi Qiang
2020-08-28 18:23 ` Jim Mattson
2020-08-31 3:15 ` Chenyi Qiang
2020-08-28 8:56 ` [PATCH 3/5] KVM: nVMX: Update VMX controls MSR according to guest CPUID after " Chenyi Qiang
2020-08-28 20:39 ` Jim Mattson
2020-09-02 18:16 ` Sean Christopherson
2020-09-02 18:32 ` Jim Mattson
2020-09-11 17:09 ` Paolo Bonzini [this message]
2020-08-28 8:56 ` [PATCH 4/5] KVM: nVMX: Fix the update value of nested load IA32_PERF_GLOBAL_CTRL control Chenyi Qiang
2020-08-28 18:29 ` Jim Mattson
2020-08-28 8:56 ` [PATCH 5/5] KVM: nVMX: Simplify the initialization of nested_vmx_msrs Chenyi Qiang
2020-09-11 17:11 ` [PATCH 0/5] Fix nested VMX controls MSRs Paolo Bonzini
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