Re: [PATCH] KVM: x86: Set BHI_NO in guest when host is not affected by BHI

Nikolay Borisov <nik.borisov@xxxxxxxx> · Thu, 11 Apr 2024 10:51:58 +0300

On 11.04.24 г. 10:24 ч., Alexandre Chartre wrote:
When a system is not affected by the BHI bug then KVM should
configure guests with BHI_NO to ensure they won't enable any
BHI mitigation.

Signed-off-by: Alexandre Chartre <alexandre.chartre@xxxxxxxxxx>
---
  arch/x86/kvm/x86.c | 3 +++
  1 file changed, 3 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 984ea2089efc..f43d3c15a6b7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1678,6 +1678,9 @@ static u64 kvm_get_arch_capabilities(void)
  	if (!boot_cpu_has_bug(X86_BUG_GDS) || gds_ucode_mitigated())
  		data |= ARCH_CAP_GDS_NO;
  
+	if (!boot_cpu_has_bug(X86_BUG_BHI))
+		data |= ARCH_CAP_BHI_NO;
+
  	return data;
  }
  

Reviewed-by: Nikolay Borisov <nik.borisov@xxxxxxxx>







