[PATCH v8 10/26] arm64: kvm: Unmask PMR before entering guest
From: Julien Thierry <hidden>
Date: 2019-01-08 14:08:25
Also in:
kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Interrupts masked by ICC_PMR_EL1 will not be signaled to the CPU. This means that hypervisor will not receive masked interrupts while running a guest. Avoid this by making sure ICC_PMR_EL1 is unmasked when we enter a guest. Signed-off-by: Julien Thierry <redacted> Cc: Christoffer Dall <redacted> Cc: Marc Zyngier <redacted> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <redacted> Cc: kvmarm@lists.cs.columbia.edu --- arch/arm64/include/asm/kvm_host.h | 12 ++++++++++++ arch/arm64/kvm/hyp/switch.c | 16 ++++++++++++++++ 2 files changed, 28 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 7732d0b..a1f9f55 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h@@ -24,6 +24,7 @@ #include <linux/types.h> #include <linux/kvm_types.h> +#include <asm/arch_gicv3.h> #include <asm/cpufeature.h> #include <asm/daifflags.h> #include <asm/fpsimd.h>
@@ -474,6 +475,17 @@ static inline int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu) static inline void kvm_arm_vhe_guest_enter(void) { local_daif_mask(); + + /* + * Having IRQs masked via PMR when entering the guest means the GIC + * will not signal the CPU of interrupts of lower priority, and the + * only way to get out will be via guest exceptions. + * Naturally, we want to avoid this. + */ + if (system_uses_irq_prio_masking()) { + gic_write_pmr(GIC_PRIO_IRQON); + dsb(sy); + } } static inline void kvm_arm_vhe_guest_exit(void)
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index b0b1478..6a4c2d6 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c@@ -22,6 +22,7 @@ #include <kvm/arm_psci.h> +#include <asm/arch_gicv3.h> #include <asm/cpufeature.h> #include <asm/kvm_asm.h> #include <asm/kvm_emulate.h>
@@ -521,6 +522,17 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) struct kvm_cpu_context *guest_ctxt; u64 exit_code; + /* + * Having IRQs masked via PMR when entering the guest means the GIC + * will not signal the CPU of interrupts of lower priority, and the + * only way to get out will be via guest exceptions. + * Naturally, we want to avoid this. + */ + if (system_uses_irq_prio_masking()) { + gic_write_pmr(GIC_PRIO_IRQON); + dsb(sy); + } + vcpu = kern_hyp_va(vcpu); host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
@@ -573,6 +585,10 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) */ __debug_switch_to_host(vcpu); + /* Returning to host will clear PSR.I, remask PMR if needed */ + if (system_uses_irq_prio_masking()) + gic_write_pmr(GIC_PRIO_IRQOFF); + return exit_code; }
--
1.9.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel