linux-kernel - [PATCH v2 3/3] KVM: x86: Open code supported XCR0 calculation in kvm_vcpu_after_set

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: <20230503160838.3412617-4-seanjc@google.com>
Date:   Wed,  3 May 2023 09:08:38 -0700
From:   Sean Christopherson <seanjc@...gle.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Kai Huang <kai.huang@...el.com>
Subject: [PATCH v2 3/3] KVM: x86: Open code supported XCR0 calculation in kvm_vcpu_after_set_cpuid()

Drop cpuid_get_supported_xcr0() now that its bastardized usage in
__kvm_update_cpuid_runtime() is gone, and open code the logic in its sole
caller, kvm_vcpu_after_set_cpuid().

No functional change intended.

Reviewed-by: Kai Huang <kai.huang@...el.com>
Tested-by: Kai Huang <kai.huang@...el.com>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/cpuid.c | 27 ++++++++++-----------------
 1 file changed, 10 insertions(+), 17 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 0c9660a07b23..491c88e196c1 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -234,21 +234,6 @@ void kvm_update_pv_runtime(struct kvm_vcpu *vcpu)
 		vcpu->arch.pv_cpuid.features = best->eax;
 }
 
-/*
- * Calculate guest's supported XCR0 taking into account guest CPUID data and
- * KVM's supported XCR0 (comprised of host's XCR0 and KVM_SUPPORTED_XCR0).
- */
-static u64 cpuid_get_supported_xcr0(struct kvm_cpuid_entry2 *entries, int nent)
-{
-	struct kvm_cpuid_entry2 *best;
-
-	best = cpuid_entry2_find(entries, nent, 0xd, 0);
-	if (!best)
-		return 0;
-
-	return (best->eax | ((u64)best->edx << 32)) & kvm_caps.supported_xcr0;
-}
-
 static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *entries,
 				       int nent)
 {
@@ -323,8 +308,16 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 		kvm_apic_set_version(vcpu);
 	}
 
-	vcpu->arch.guest_supported_xcr0 =
-		cpuid_get_supported_xcr0(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent);
+	/*
+	 * Calculate guest's supported XCR0 taking into account guest CPUID data and
+	 * KVM's supported XCR0 (comprised of host's XCR0 and KVM_SUPPORTED_XCR0).
+	 */
+	best = kvm_find_cpuid_entry_index(vcpu, 0xd, 0);
+	if (!best)
+		vcpu->arch.guest_supported_xcr0 = 0;
+	else
+		vcpu->arch.guest_supported_xcr0 = (best->eax | ((u64)best->edx << 32)) &
+						  kvm_caps.supported_xcr0;
 
 	/*
 	 * FP+SSE can always be saved/restored via KVM_{G,S}ET_XSAVE, even if
-- 
2.40.1.495.gc816e09b53d-goog