linux-kernel - [PATCH v2 30/46] KVM: SVM: Tweak order of cr0/cr4/efer writes at RESET/INIT

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]

Message-Id: <20210713163324.627647-31-seanjc@google.com>
Date:   Tue, 13 Jul 2021 09:33:08 -0700
From:   Sean Christopherson <seanjc@...gle.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Reiji Watanabe <reijiw@...gle.com>
Subject: [PATCH v2 30/46] KVM: SVM: Tweak order of cr0/cr4/efer writes at RESET/INIT

Hoist svm_set_cr0() up in the sequence of register initialization during
vCPU RESET/INIT, purely to match VMX so that a future patch can move the
sequences to common x86.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/svm/svm.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 0101646e42e0..875d68c4cb9b 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1262,18 +1262,13 @@ static void init_vmcb(struct kvm_vcpu *vcpu)
 	init_sys_seg(&save->ldtr, SEG_TYPE_LDT);
 	init_sys_seg(&save->tr, SEG_TYPE_BUSY_TSS16);
 
+	svm_set_cr0(vcpu, X86_CR0_NW | X86_CR0_CD | X86_CR0_ET);
 	svm_set_cr4(vcpu, 0);
 	svm_set_efer(vcpu, 0);
 	save->dr6 = 0xffff0ff0;
 	kvm_set_rflags(vcpu, X86_EFLAGS_FIXED);
 	vcpu->arch.regs[VCPU_REGS_RIP] = 0x0000fff0;
 
-	/*
-	 * svm_set_cr0() sets PG and WP and clears NW and CD on save->cr0.
-	 * It also updates the guest-visible cr0 value.
-	 */
-	svm_set_cr0(vcpu, X86_CR0_NW | X86_CR0_CD | X86_CR0_ET);
-
 	save->cr4 = X86_CR4_PAE;
 
 	if (npt_enabled) {
-- 
2.32.0.93.g670b81a890-goog