From: Sean Christopherson <seanjc@xxxxxxxxxx>
commit a2b07fa7b93321c059af0c6d492cc9a4f1e390aa upstream.
Disable SVM and more importantly force GIF=1 when halting a CPU or
rebooting the machine. Similar to VMX, SVM allows software to block
INITs via CLGI, and thus can be problematic for a crash/reboot. The
window for failure is smaller with SVM as INIT is only blocked while
GIF=0, i.e. between CLGI and STGI, but the window does exist.
Fixes: fba4f472b33a ("x86/reboot: Turn off KVM when halting a CPU")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221130233650.1404148-5-seanjc@xxxxxxxxxx
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/smp.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -33,7 +33,7 @@
#include <asm/mce.h>
#include <asm/trace/irq_vectors.h>
#include <asm/kexec.h>
-#include <asm/virtext.h>
+#include <asm/reboot.h>
/*
* Some notes on x86 processor bugs affecting SMP operation:
@@ -163,7 +163,7 @@ static int smp_stop_nmi_callback(unsigne
if (raw_smp_processor_id() == atomic_read(&stopping_cpu))
return NMI_HANDLED;
- cpu_emergency_vmxoff();
+ cpu_emergency_disable_virtualization();
stop_this_cpu(NULL);
return NMI_HANDLED;
@@ -176,7 +176,7 @@ static int smp_stop_nmi_callback(unsigne
asmlinkage __visible void smp_reboot_interrupt(void)
{
ipi_entering_ack_irq();
- cpu_emergency_vmxoff();
+ cpu_emergency_disable_virtualization();
stop_this_cpu(NULL);
irq_exit();
}
