linux-kernel - [PATCH 5.10 032/167] KVM: x86/pmu: Clear anythread deprecated bit when 0xa leaf is unsupported on the SVM

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Date:   Mon, 26 Jul 2021 17:37:45 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Like Xu <likexu@...cent.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.10 032/167] KVM: x86/pmu: Clear anythread deprecated bit when 0xa leaf is unsupported on the SVM

From: Like Xu <like.xu.linux@...il.com>

[ Upstream commit 7234c362ccb3c2228f06f19f93b132de9cfa7ae4 ]

The AMD platform does not support the functions Ah CPUID leaf. The returned
results for this entry should all remain zero just like the native does:

AMD host:
   0x0000000a 0x00: eax=0x00000000 ebx=0x00000000 ecx=0x00000000 edx=0x00000000
(uncanny) AMD guest:
   0x0000000a 0x00: eax=0x00000000 ebx=0x00000000 ecx=0x00000000 edx=0x00008000

Fixes: cadbaa039b99 ("perf/x86/intel: Make anythread filter support conditional")
Signed-off-by: Like Xu <likexu@...cent.com>
Message-Id: <20210628074354.33848-1-likexu@...cent.com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 arch/x86/kvm/cpuid.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 7a3fbf3b796e..41b0dc37720e 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -684,7 +684,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 
 		edx.split.num_counters_fixed = min(cap.num_counters_fixed, MAX_FIXED_COUNTERS);
 		edx.split.bit_width_fixed = cap.bit_width_fixed;
-		edx.split.anythread_deprecated = 1;
+		if (cap.version)
+			edx.split.anythread_deprecated = 1;
 		edx.split.reserved1 = 0;
 		edx.split.reserved2 = 0;
 
-- 
2.30.2