[PATCH v5 14/27] arm64: kvm: Unmask PMR before entering guest
From: Julien Thierry <hidden>
Date: 2018-08-28 15:52:24
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. Tested-by: Daniel Thompson <redacted> 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 at lists.cs.columbia.edu --- arch/arm64/include/asm/kvm_host.h | 12 ++++++++++++ arch/arm64/kvm/hyp/switch.c | 17 +++++++++++++++++ 2 files changed, 29 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index f26055f..9689592 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>
@@ -466,6 +467,17 @@ 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 (gic_prio_masking_enabled()) { + gic_write_pmr(ICC_PMR_EL1_UNMASKED); + 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 d496ef5..074ab21 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>
@@ -533,6 +534,19 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) struct kvm_cpu_context *host_ctxt; struct kvm_cpu_context *guest_ctxt; u64 exit_code; + u32 host_pmr = ICC_PMR_EL1_UNMASKED; + + /* + * 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 (gic_prio_masking_enabled()) { + host_pmr = gic_read_pmr(); + gic_write_pmr(ICC_PMR_EL1_UNMASKED); + dsb(sy); + } vcpu = kern_hyp_va(vcpu);
@@ -586,6 +600,9 @@ int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) */ __debug_switch_to_host(vcpu); + if (gic_prio_masking_enabled()) + gic_write_pmr(host_pmr); + return exit_code; } --
1.9.1