| Message ID | 20230719215725.799162-1-rananta@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] KVM: arm64: Fix hardware enable/disable flows for pKVM | expand |
On Wed, 19 Jul 2023 22:57:25 +0100, Raghavendra Rao Ananta <rananta@google.com> wrote: > > 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@linux.dev> > Suggested-by: Oliver Upton <oliver.upton@linux.dev> > Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> > --- > arch/arm64/kvm/arm.c | 14 ++++---------- > 1 file changed, 4 insertions(+), 10 deletions(-) > > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index c2c14059f6a8..010ebfa69650 100644 > --- a/arch/arm64/kvm/arm.c > +++ b/arch/arm64/kvm/arm.c > @@ -1867,14 +1867,10 @@ static void _kvm_arch_hardware_enable(void *discard) > > int kvm_arch_hardware_enable(void) > { > - int 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(); > > return 0; > } > @@ -1889,10 +1885,8 @@ static void _kvm_arch_hardware_disable(void *discard) > > 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); Note that this will likely conflict with the preemption disabling patch that is on its way to upstream. Otherwise: Acked-by: Marc Zyngier <maz@kernel.org> M.
On Wed, 19 Jul 2023 21:57:25 +0000, Raghavendra Rao Ananta wrote: > 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. > > [...] Applied to kvmarm/fixes, thanks! [1/1] KVM: arm64: Fix hardware enable/disable flows for pKVM https://git.kernel.org/kvmarm/kvmarm/c/c718ca0e9940 -- Best, Oliver
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index c2c14059f6a8..010ebfa69650 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1867,14 +1867,10 @@ static void _kvm_arch_hardware_enable(void *discard) int kvm_arch_hardware_enable(void) { - int 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(); return 0; } @@ -1889,10 +1885,8 @@ static void _kvm_arch_hardware_disable(void *discard) 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);
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@linux.dev> Suggested-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> --- arch/arm64/kvm/arm.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-)