On 11/6/2024 09:03, Sean Christopherson wrote:
+KVM, given that this quite obviously affects KVM...
On Tue, Nov 05, 2024, Mario Limonciello wrote:
From: Mario Limonciello <mario.limonciello@xxxxxxx>
A number of Zen4 client SoCs advertise the ability to use virtualized
VMLOAD/VMSAVE, but using these instructions is reported to be a cause
of a random host reboot.
These instructions aren't intended to be advertised on Zen4 client
so clear the capability.
Cc: stable@xxxxxxxxxxxxxxx
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219009
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
arch/x86/kernel/cpu/amd.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 015971adadfc7..ecd42c2b3242e 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -924,6 +924,17 @@ static void init_amd_zen4(struct cpuinfo_x86 *c)
{
if (!cpu_has(c, X86_FEATURE_HYPERVISOR))
msr_set_bit(MSR_ZEN4_BP_CFG, MSR_ZEN4_BP_CFG_SHARED_BTB_FIX_BIT);
+
+ /*
+ * These Zen4 SoCs advertise support for virtualized VMLOAD/VMSAVE
+ * in some BIOS versions but they can lead to random host reboots.
Uh, CPU bug? Erratum?
BIOS bug. Those shouldn't have been advertised.
+ */
+ switch (c->x86_model) {
+ case 0x18 ... 0x1f:
+ case 0x60 ... 0x7f:
+ clear_cpu_cap(c, X86_FEATURE_V_VMSAVE_VMLOAD);
+ break;
+ }
}
static void init_amd_zen5(struct cpuinfo_x86 *c)
--
2.43.0
