This is a note to let you know that I've just added the patch titled
KVM: arm64: Fix hardware enable/disable flows for pKVM
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-arm64-fix-hardware-enable-disable-flows-for-pkvm.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From c718ca0e99401d80d2480c08e1b02cf5f7cd7033 Mon Sep 17 00:00:00 2001
From: Raghavendra Rao Ananta <rananta@xxxxxxxxxx>
Date: Wed, 19 Jul 2023 17:54:00 +0000
Subject: KVM: arm64: Fix hardware enable/disable flows for pKVM
From: Raghavendra Rao Ananta <rananta@xxxxxxxxxx>
commit c718ca0e99401d80d2480c08e1b02cf5f7cd7033 upstream.
When running in protected mode, the hyp stub is disabled after pKVM is
initialized, meaning the host cannot enable/disable the hyp at
runtime. As such, kvm_arm_hardware_enabled is always 1 after
initialization, and kvm_arch_hardware_enable() never enables the vgic
maintenance irq or timer irqs.
Unconditionally enable/disable the vgic + timer irqs in the respective
calls, instead relying on the percpu bookkeeping in the generic code
to keep track of which cpus have the interrupts unmasked.
Fixes: 466d27e48d7c ("KVM: arm64: Simplify the CPUHP logic")
Reported-by: Oliver Upton <oliver.upton@xxxxxxxxx>
Suggested-by: Oliver Upton <oliver.upton@xxxxxxxxx>
Signed-off-by: Raghavendra Rao Ananta <rananta@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230719175400.647154-1-rananta@xxxxxxxxxx
Acked-by: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: Oliver Upton <oliver.upton@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/kvm/arm.c | 15 ++++-----------
1 file changed, 4 insertions(+), 11 deletions(-)
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1800,8 +1800,6 @@ static void _kvm_arch_hardware_enable(vo
int kvm_arch_hardware_enable(void)
{
- int was_enabled;
-
/*
* Most calls to this function are made with migration
* disabled, but not with preemption disabled. The former is
@@ -1810,13 +1808,10 @@ int kvm_arch_hardware_enable(void)
*/
preempt_disable();
- was_enabled = __this_cpu_read(kvm_arm_hardware_enabled);
_kvm_arch_hardware_enable(NULL);
- if (!was_enabled) {
- kvm_vgic_cpu_up();
- kvm_timer_cpu_up();
- }
+ kvm_vgic_cpu_up();
+ kvm_timer_cpu_up();
preempt_enable();
@@ -1833,10 +1828,8 @@ static void _kvm_arch_hardware_disable(v
void kvm_arch_hardware_disable(void)
{
- if (__this_cpu_read(kvm_arm_hardware_enabled)) {
- kvm_timer_cpu_down();
- kvm_vgic_cpu_down();
- }
+ kvm_timer_cpu_down();
+ kvm_vgic_cpu_down();
if (!is_protected_kvm_enabled())
_kvm_arch_hardware_disable(NULL);
Patches currently in stable-queue which might be from rananta@xxxxxxxxxx are
queue-6.4/kvm-arm64-fix-hardware-enable-disable-flows-for-pkvm.patch
