linux-kernel - [PATCH 41/61] KVM: x86: Move XSAVES CPUID adjust to VMX's KVM cpu cap update

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: <20200201185218.24473-42-sean.j.christopherson@intel.com>
Date:   Sat,  1 Feb 2020 10:51:58 -0800
From:   Sean Christopherson <sean.j.christopherson@...el.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <sean.j.christopherson@...el.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
Subject: [PATCH 41/61] KVM: x86: Move XSAVES CPUID adjust to VMX's KVM cpu cap update

Move the clearing of the XSAVES CPUID bit into VMX, which has a separate
VMCS control to enable XSAVES in non-root, to eliminate the last ugly
renmant of the undesirable "unsigned f_* = *_supported ? F(*) : 0"
pattern in the common CPUID handling code.

Drop ->xsaves_supported(), CPUID adjustment was the only user.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
---
 arch/x86/include/asm/kvm_host.h | 1 -
 arch/x86/kvm/cpuid.c            | 4 ----
 arch/x86/kvm/svm.c              | 6 ------
 arch/x86/kvm/vmx/vmx.c          | 5 ++++-
 4 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ba828569cda5..dd690fb5ceca 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1163,7 +1163,6 @@ struct kvm_x86_ops {
 	void (*handle_exit_irqoff)(struct kvm_vcpu *vcpu,
 		enum exit_fastpath_completion *exit_fastpath);
 
-	bool (*xsaves_supported)(void);
 	bool (*umip_emulated)(void);
 	bool (*pt_supported)(void);
 
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index c2a4c9df49a9..77a6c1db138d 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -626,10 +626,6 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 			goto out;
 
 		cpuid_entry_mask(entry, CPUID_D_1_EAX);
-
-		if (!kvm_x86_ops->xsaves_supported())
-			cpuid_entry_clear(entry, X86_FEATURE_XSAVES);
-
 		if (entry->eax & (F(XSAVES)|F(XSAVEC)))
 			entry->ebx = xstate_required_size(supported_xcr0, true);
 		else
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index f98a192459f7..7cb05945162e 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6080,11 +6080,6 @@ static bool svm_rdtscp_supported(void)
 	return boot_cpu_has(X86_FEATURE_RDTSCP);
 }
 
-static bool svm_xsaves_supported(void)
-{
-	return boot_cpu_has(X86_FEATURE_XSAVES);
-}
-
 static bool svm_umip_emulated(void)
 {
 	return false;
@@ -7455,7 +7450,6 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.cpuid_update = svm_cpuid_update,
 
 	.rdtscp_supported = svm_rdtscp_supported,
-	.xsaves_supported = svm_xsaves_supported,
 	.umip_emulated = svm_umip_emulated,
 	.pt_supported = svm_pt_supported,
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index bae915431c72..cfd0ef314176 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7131,6 +7131,10 @@ static __init void vmx_set_cpu_caps(void)
 	    boot_cpu_has(X86_FEATURE_OSPKE))
 		kvm_cpu_cap_set(X86_FEATURE_PKU);
 
+	/* CPUID 0xD.1 */
+	if (!vmx_xsaves_supported())
+		kvm_cpu_cap_clear(X86_FEATURE_XSAVES);
+
 	/* CPUID 0x80000001 */
 	if (!cpu_has_vmx_rdtscp())
 		kvm_cpu_cap_clear(X86_FEATURE_RDTSCP);
@@ -7886,7 +7890,6 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 
 	.check_intercept = vmx_check_intercept,
 	.handle_exit_irqoff = vmx_handle_exit_irqoff,
-	.xsaves_supported = vmx_xsaves_supported,
 	.umip_emulated = vmx_umip_emulated,
 	.pt_supported = vmx_pt_supported,
 
-- 
2.24.1