kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Yang Weijiang <weijiang.yang@intel.com>
To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	pbonzini@redhat.com, jmattson@google.com,
	sean.j.christopherson@intel.com
Cc: yu.c.zhang@linux.intel.com, Yang Weijiang <weijiang.yang@intel.com>
Subject: [PATCH v9 5/7] KVM: X86: Enable CET bits update in IA32_XSS
Date: Fri, 27 Dec 2019 10:11:31 +0800	[thread overview]
Message-ID: <20191227021133.11993-6-weijiang.yang@intel.com> (raw)
In-Reply-To: <20191227021133.11993-1-weijiang.yang@intel.com>

Previously, KVM did not support setting any bits in XSS
so it's hardcoded to check and inject a #GP if Guest
attempted to write a non-zero value to XSS, now it supports
CET related bits setting.

Co-developed-by: Zhang Yi Z <yi.z.zhang@linux.intel.com>
Signed-off-by: Zhang Yi Z <yi.z.zhang@linux.intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/cpuid.c            | 12 ++++++++++--
 arch/x86/kvm/vmx/vmx.c          |  6 +-----
 3 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4e59f17ded50..64bf379381e4 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -620,6 +620,7 @@ struct kvm_vcpu_arch {
 
 	u64 xcr0;
 	u64 guest_supported_xcr0;
+	u64 guest_supported_xss;
 	u32 guest_xstate_size;
 
 	struct kvm_pio_request pio;
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 546cfe123ba7..126a31b99823 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -125,8 +125,16 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu)
 	}
 
 	best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
-	if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
-		best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
+	if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) {
+		u64 xstate = vcpu->arch.xcr0 | vcpu->arch.ia32_xss;
+
+		best->ebx = xstate_required_size(xstate, true);
+		vcpu->arch.guest_supported_xss =
+			(best->ecx | ((u64)best->edx << 32)) &
+			kvm_supported_xss();
+	} else {
+		vcpu->arch.guest_supported_xss = 0;
+	}
 
 	/*
 	 * The existing code assumes virtual address is 48-bit or 57-bit in the
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 95063cc7da89..0a75b65d03f0 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2081,11 +2081,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		     !(guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) &&
 		       guest_cpuid_has(vcpu, X86_FEATURE_XSAVES))))
 			return 1;
-		/*
-		 * The only supported bit as of Skylake is bit 8, but
-		 * it is not supported on KVM.
-		 */
-		if (data != 0)
+		if (data & ~vcpu->arch.guest_supported_xss)
 			return 1;
 		vcpu->arch.ia32_xss = data;
 		if (vcpu->arch.ia32_xss != host_xss)
-- 
2.17.2


  parent reply	other threads:[~2019-12-27  2:07 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-27  2:11 [PATCH v9 0/7] Introduce support for guest CET feature Yang Weijiang
2019-12-27  2:11 ` [PATCH v9 1/7] KVM: CPUID: Fix IA32_XSS support in CPUID(0xd,i) enumeration Yang Weijiang
2020-03-05 14:51   ` Paolo Bonzini
2020-03-06  0:38     ` Yang Weijiang
2019-12-27  2:11 ` [PATCH v9 2/7] KVM: VMX: Define CET VMCS fields and #CP flag Yang Weijiang
2020-03-03 21:42   ` Sean Christopherson
2020-03-04  8:44     ` Yang Weijiang
2019-12-27  2:11 ` [PATCH v9 3/7] KVM: VMX: Pass through CET related MSRs Yang Weijiang
2020-03-03 21:51   ` Sean Christopherson
2020-03-04  8:46     ` Yang Weijiang
2019-12-27  2:11 ` [PATCH v9 4/7] KVM: VMX: Load CET states on vmentry/vmexit Yang Weijiang
2020-03-03 22:06   ` Sean Christopherson
2020-03-04  8:55     ` Yang Weijiang
2019-12-27  2:11 ` Yang Weijiang [this message]
2019-12-27  2:11 ` [PATCH v9 6/7] KVM: X86: Load guest fpu state when accessing MSRs managed by XSAVES Yang Weijiang
2019-12-27  2:11 ` [PATCH v9 7/7] KVM: X86: Add user-space access interface for CET MSRs Yang Weijiang
2020-03-03 22:28   ` Sean Christopherson
2020-03-04 15:18     ` Yang Weijiang
2020-03-04 15:45       ` Sean Christopherson
2020-03-05 12:31         ` Yang Weijiang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191227021133.11993-6-weijiang.yang@intel.com \
    --to=weijiang.yang@intel.com \
    --cc=jmattson@google.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=sean.j.christopherson@intel.com \
    --cc=yu.c.zhang@linux.intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).