From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
To: kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Maxim Levitsky <mlevitsk@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
linux-kernel@vger.kernel.org,
Emanuele Giuseppe Esposito <eesposit@redhat.com>
Subject: [PATCH v2 3/4] nSVM: use vmcb_save_area_cached in nested_vmcb_valid_sregs()
Date: Fri, 17 Sep 2021 08:03:28 -0400 [thread overview]
Message-ID: <20210917120329.2013766-4-eesposit@redhat.com> (raw)
In-Reply-To: <20210917120329.2013766-1-eesposit@redhat.com>
Now that struct vmcb_save_area_cached contains the required
vmcb fields values (done in nested_load_save_from_vmcb12()),
check them to see if they are correct in nested_vmcb_valid_sregs().
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
arch/x86/kvm/svm/nested.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index fcbb66915403..7e4cd134946f 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -278,7 +278,7 @@ static bool nested_vmcb_check_controls(struct kvm_vcpu *vcpu,
/* Common checks that apply to both L1 and L2 state. */
static bool nested_vmcb_valid_sregs(struct kvm_vcpu *vcpu,
- struct vmcb_save_area *save)
+ struct vmcb_save_area_cached *save)
{
/*
* FIXME: these should be done after copying the fields,
@@ -671,7 +671,7 @@ int nested_svm_vmrun(struct kvm_vcpu *vcpu)
nested_load_control_from_vmcb12(svm, &vmcb12->control);
nested_load_save_from_vmcb12(svm, &vmcb12->save);
- if (!nested_vmcb_valid_sregs(vcpu, &vmcb12->save) ||
+ if (!nested_vmcb_valid_sregs(vcpu, &svm->nested.save) ||
!nested_vmcb_check_controls(vcpu, &svm->nested.ctl)) {
vmcb12->control.exit_code = SVM_EXIT_ERR;
vmcb12->control.exit_code_hi = 0;
@@ -1368,11 +1368,12 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
* Validate host state saved from before VMRUN (see
* nested_svm_check_permissions).
*/
+ nested_load_save_from_vmcb12(svm, save);
if (!(save->cr0 & X86_CR0_PG) ||
!(save->cr0 & X86_CR0_PE) ||
(save->rflags & X86_EFLAGS_VM) ||
- !nested_vmcb_valid_sregs(vcpu, save))
- goto out_free;
+ !nested_vmcb_valid_sregs(vcpu, &svm->nested.save))
+ goto out_free_save;
/*
* While the nested guest CR3 is already checked and set by
@@ -1384,7 +1385,7 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
ret = nested_svm_load_cr3(&svm->vcpu, vcpu->arch.cr3,
nested_npt_enabled(svm), false);
if (WARN_ON_ONCE(ret))
- goto out_free;
+ goto out_free_save;
/*
@@ -1408,12 +1409,15 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
svm_copy_vmrun_state(&svm->vmcb01.ptr->save, save);
nested_load_control_from_vmcb12(svm, ctl);
- nested_load_save_from_vmcb12(svm, save);
svm_switch_vmcb(svm, &svm->nested.vmcb02);
nested_vmcb02_prepare_control(svm);
kvm_make_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu);
ret = 0;
+
+out_free_save:
+ memset(&svm->nested.save, 0, sizeof(struct vmcb_save_area_cached));
+
out_free:
kfree(save);
kfree(ctl);
--
2.27.0
next prev parent reply other threads:[~2021-09-17 12:03 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-17 12:03 [PATCH v2 0/4] KVM: nSVM: avoid TOC/TOU race when checking vmcb12 Emanuele Giuseppe Esposito
2021-09-17 12:03 ` [PATCH v2 1/4] KVM: nSVM: move nested_vmcb_check_cr3_cr4 logic in nested_vmcb_valid_sregs Emanuele Giuseppe Esposito
2021-09-17 12:03 ` [PATCH v2 2/4] nSVM: introduce smv->nested.save to cache save area fields Emanuele Giuseppe Esposito
2021-09-28 16:51 ` Paolo Bonzini
2021-09-17 12:03 ` Emanuele Giuseppe Esposito [this message]
2021-09-17 12:03 ` [PATCH v2 4/4] nSVM: use svm->nested.save to load vmcb12 registers and avoid TOC/TOU races Emanuele Giuseppe Esposito
2021-09-28 16:52 ` [PATCH v2 0/4] KVM: nSVM: avoid TOC/TOU race when checking vmcb12 Paolo Bonzini
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