[SRU][J][PATCH 3/3] x86/CPU/AMD: Clear virtualized VMLOAD/VMSAVE on Zen4 client

[Juerg Haefliger]

From: Mario Limonciello <mario.limonciello at amd.com>

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.

Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp at alien8.de>
Cc: stable at vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219009
(backported from commit a5ca1dc46a6b610dd4627d8b633d6c84f9724ef0)
[juergh: Adjusted context due to missing commit:
 794c68b20408 ("x86/CPU/AMD: Get rid of amd_erratum_1485[]")]
CVE-2024-53114
Signed-off-by: Juerg Haefliger <juerg.haefliger at canonical.com>
---
 arch/x86/kernel/cpu/amd.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 9399defbf173..c7daae834c11 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -1157,6 +1157,16 @@ static void init_amd_zen3(struct cpuinfo_x86 *c)
 
 static void init_amd_zen4(struct cpuinfo_x86 *c)
 {
+	/*
+	 * These Zen4 SoCs advertise support for virtualized VMLOAD/VMSAVE
+	 * in some BIOS versions but they can lead to random host reboots.
+	 */
+	switch (c->x86_model) {
+	case 0x18 ... 0x1f:
+	case 0x60 ... 0x7f:
+		clear_cpu_cap(c, X86_FEATURE_V_VMSAVE_VMLOAD);
+		break;
+	}
 }
 
 static void init_amd(struct cpuinfo_x86 *c)
-- 
2.48.1