computing-offload/generic_vdpa/qemu/target-i386-Allow-MCDT_NO-if-host-supports.patch
jiangdongxu 79c4324644 add generic_vdpa basecode
Change-Id: I2d302dda68298877c65c99147f5bf22186a59aac
2024-09-19 17:19:46 +08:00

44 lines
1.7 KiB
Diff

From 6beadcde4d28a1e4ad3267b7702162ecf9d4541b Mon Sep 17 00:00:00 2001
From: Tao Su <tao1.su@linux.intel.com>
Date: Thu, 6 Jul 2023 13:49:46 +0800
Subject: [PATCH] target/i386: Allow MCDT_NO if host supports
commit ba3709feaab44631315e02cd793cfccae4c6bd2a upstream.
MCDT_NO bit indicates HW contains the security fix and doesn't need to
be mitigated to avoid data-dependent behaviour for certain instructions.
It needs no hypervisor support. Treat it as supported regardless of what
KVM reports.
Intel-SIG: commit ba3709feaab4 ("target/i386: Allow MCDT_NO if host supports")
Backport allowing MCDT_NO if host supports
Signed-off-by: Tao Su <tao1.su@linux.intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-ID: <20230706054949.66556-4-tao1.su@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[ jason: amend commit log ]
Signed-off-by: Jason Zeng <jason.zeng@intel.com>
---
target/i386/kvm/kvm.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index d323d08dcb..55ee75e844 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -424,6 +424,10 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function,
uint32_t eax;
host_cpuid(7, 1, &eax, &unused, &unused, &unused);
ret |= eax & (CPUID_7_1_EAX_FZRM | CPUID_7_1_EAX_FSRS | CPUID_7_1_EAX_FSRC);
+ } else if (function == 7 && index == 2 && reg == R_EDX) {
+ uint32_t edx;
+ host_cpuid(7, 2, &unused, &unused, &unused, &edx);
+ ret |= edx & CPUID_7_2_EDX_MCDT_NO;
} else if (function == 0xd && index == 0 &&
(reg == R_EAX || reg == R_EDX)) {
/*
--
2.41.0.windows.1