linux-kernel - [PATCH 09/24] KVM: nSVM: clean up tsc

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 20 May 2020 13:21:30 -0400
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     vkuznets@...hat.com, Joerg Roedel <jroedel@...e.de>
Subject: [PATCH 09/24] KVM: nSVM: clean up tsc_offset update

Use l1_tsc_offset to compute svm->vcpu.arch.tsc_offset and
svm->vmcb->control.tsc_offset, instead of relying on hsave.

Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/x86/kvm/svm/nested.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 4f81c2196bf6..2aaa539482ae 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -241,8 +241,6 @@ static void load_nested_vmcb_control(struct vcpu_svm *svm,
 	svm->nested.intercept_dr         = control->intercept_dr;
 	svm->nested.intercept_exceptions = control->intercept_exceptions;
 	svm->nested.intercept            = control->intercept;
-
-	svm->vcpu.arch.tsc_offset += control->tsc_offset;
 }
 
 static void nested_prepare_vmcb_save(struct vcpu_svm *svm, struct vmcb *nested_vmcb)
@@ -292,7 +290,8 @@ static void nested_prepare_vmcb_control(struct vcpu_svm *svm, struct vmcb *neste
 	else
 		svm->vcpu.arch.hflags &= ~HF_VINTR_MASK;
 
-	svm->vmcb->control.tsc_offset = svm->vcpu.arch.tsc_offset;
+	svm->vmcb->control.tsc_offset = svm->vcpu.arch.tsc_offset =
+		svm->vcpu.arch.l1_tsc_offset + nested_vmcb->control.tsc_offset;
 
 	svm->vmcb->control.int_ctl = nested_vmcb->control.int_ctl | V_INTR_MASKING_MASK;
 	svm->vmcb->control.virt_ext = nested_vmcb->control.virt_ext;
@@ -557,7 +556,9 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
 	/* Restore the original control entries */
 	copy_vmcb_control_area(vmcb, hsave);
 
-	svm->vcpu.arch.tsc_offset = svm->vmcb->control.tsc_offset;
+	svm->vmcb->control.tsc_offset = svm->vcpu.arch.tsc_offset =
+		svm->vcpu.arch.l1_tsc_offset;
+
 	kvm_clear_exception_queue(&svm->vcpu);
 	kvm_clear_interrupt_queue(&svm->vcpu);
 
-- 
2.18.2