diff options
| author | Oliver Upton <oliver.upton@linux.dev> | 2024-12-19 14:41:09 -0800 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2024-12-20 09:01:25 +0000 |
| commit | 06d22a9c1b94006ebfa67693a38baed86b9a75e8 (patch) | |
| tree | c51bd30335aa3e89002d966f6565c050599c8776 | |
| parent | beb470d96cec8dd8f4e05b2135c74d828f7b114b (diff) | |
KVM: arm64: Reload vCPU for accesses to OSLAR_EL1
KVM takes ownership of the debug regs if the guest enables the OS lock,
as it needs to use MDSCR_EL1 to mask debug exceptions. Just reload the
vCPU if the guest toggles the OS lock, relying on kvm_vcpu_load_debug()
to update the debug owner and get the right trap configuration in place.
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20241219224116.3941496-13-oliver.upton@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/arm64/kvm/debug.c | 13 | ||||
| -rw-r--r-- | arch/arm64/kvm/sys_regs.c | 9 |
3 files changed, 15 insertions, 8 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index a6796a952af7..d61b8ed32a21 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1346,6 +1346,7 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu); void kvm_arm_clear_debug(struct kvm_vcpu *vcpu); void kvm_vcpu_load_debug(struct kvm_vcpu *vcpu); void kvm_debug_set_guest_ownership(struct kvm_vcpu *vcpu); +void kvm_debug_handle_oslar(struct kvm_vcpu *vcpu, u64 val); #define kvm_vcpu_os_lock_enabled(vcpu) \ (!!(__vcpu_sys_reg(vcpu, OSLSR_EL1) & OSLSR_EL1_OSLK)) diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c index a4ae17c31fa8..dec023673d4c 100644 --- a/arch/arm64/kvm/debug.c +++ b/arch/arm64/kvm/debug.c @@ -288,3 +288,16 @@ void kvm_debug_set_guest_ownership(struct kvm_vcpu *vcpu) vcpu->arch.debug_owner = VCPU_DEBUG_GUEST_OWNED; } + +void kvm_debug_handle_oslar(struct kvm_vcpu *vcpu, u64 val) +{ + if (val & OSLAR_EL1_OSLK) + __vcpu_sys_reg(vcpu, OSLSR_EL1) |= OSLSR_EL1_OSLK; + else + __vcpu_sys_reg(vcpu, OSLSR_EL1) &= ~OSLSR_EL1_OSLK; + + preempt_disable(); + kvm_arch_vcpu_put(vcpu); + kvm_arch_vcpu_load(vcpu, smp_processor_id()); + preempt_enable(); +} diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 66db77fb6201..ed4adbf5a25e 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -570,17 +570,10 @@ static bool trap_oslar_el1(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - u64 oslsr; - if (!p->is_write) return read_from_write_only(vcpu, p, r); - /* Forward the OSLK bit to OSLSR */ - oslsr = __vcpu_sys_reg(vcpu, OSLSR_EL1) & ~OSLSR_EL1_OSLK; - if (p->regval & OSLAR_EL1_OSLK) - oslsr |= OSLSR_EL1_OSLK; - - __vcpu_sys_reg(vcpu, OSLSR_EL1) = oslsr; + kvm_debug_handle_oslar(vcpu, p->regval); return true; } |