Kernel KVM virtualization development
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From: Wanpeng Li <kernellwp@gmail.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>
Subject: [PATCH] KVM: X86: Expose KVM_HINTS_REALTIME in KVM_GET_SUPPORTED_CPUID
Date: Thu, 22 Oct 2020 09:34:35 +0800	[thread overview]
Message-ID: <1603330475-7063-1-git-send-email-wanpengli@tencent.com> (raw)

From: Wanpeng Li <wanpengli@tencent.com>

Per KVM_GET_SUPPORTED_CPUID ioctl documentation:

This ioctl returns x86 cpuid features which are supported by both the 
hardware and kvm in its default configuration.

A well-behaved userspace should not set the bit if it is not supported.

Suggested-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
---
 arch/x86/kvm/cpuid.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 06a278b..225d251 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -789,7 +789,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 
 		entry->ebx = 0;
 		entry->ecx = 0;
-		entry->edx = 0;
+		entry->edx = (1 << KVM_HINTS_REALTIME);
 		break;
 	case 0x80000000:
 		entry->eax = min(entry->eax, 0x8000001f);
-- 
2.7.4


             reply	other threads:[~2020-10-22  1:34 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-22  1:34 Wanpeng Li [this message]
2020-10-22 13:02 ` [PATCH] KVM: X86: Expose KVM_HINTS_REALTIME in KVM_GET_SUPPORTED_CPUID Paolo Bonzini
2020-10-22 13:25   ` Vitaly Kuznetsov
2020-10-22 13:31   ` Xiaoyao Li
2020-10-22 14:06     ` Paolo Bonzini
2020-10-22 14:28       ` Xiaoyao Li
2020-10-22 14:44         ` Paolo Bonzini
2020-10-22 16:35   ` Jim Mattson
2020-10-22 16:37     ` Paolo Bonzini
2020-10-22 17:13       ` Jim Mattson
2020-10-23  9:07         ` Paolo Bonzini
2020-10-23 17:03           ` Jim Mattson
2020-10-23  0:27   ` Wanpeng Li

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