From 0f1a6c5c9784eff7e31e4915e17285fb89ad3644 Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Fri, 31 Jan 2025 22:29:24 +0000 Subject: KVM: arm64: Flush/sync debug state in protected mode The recent changes to debug state management broke self-hosted debug for guests when running in protected mode, since both the debug owner and the debug state itself aren't shared with the hyp's view of the vcpu. Fix it by flushing/syncing the relevant bits with the hyp vcpu. Fixes: beb470d96cec ("KVM: arm64: Use debug_owner to track if debug regs need save/restore") Reported-by: Mark Brown Closes: https://lore.kernel.org/kvmarm/5f62740f-a065-42d9-9f56-8fb648b9c63f@sirena.org.uk/ Signed-off-by: Oliver Upton Link: https://lore.kernel.org/r/20250131222922.1548780-3-oliver.upton@linux.dev Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'arch/arm64/kvm/hyp') diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 5c134520e180..6e12c070832f 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -91,11 +91,34 @@ static void fpsimd_sve_sync(struct kvm_vcpu *vcpu) *host_data_ptr(fp_owner) = FP_STATE_HOST_OWNED; } +static void flush_debug_state(struct pkvm_hyp_vcpu *hyp_vcpu) +{ + struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu; + + hyp_vcpu->vcpu.arch.debug_owner = host_vcpu->arch.debug_owner; + + if (kvm_guest_owns_debug_regs(&hyp_vcpu->vcpu)) + hyp_vcpu->vcpu.arch.vcpu_debug_state = host_vcpu->arch.vcpu_debug_state; + else if (kvm_host_owns_debug_regs(&hyp_vcpu->vcpu)) + hyp_vcpu->vcpu.arch.external_debug_state = host_vcpu->arch.external_debug_state; +} + +static void sync_debug_state(struct pkvm_hyp_vcpu *hyp_vcpu) +{ + struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu; + + if (kvm_guest_owns_debug_regs(&hyp_vcpu->vcpu)) + host_vcpu->arch.vcpu_debug_state = hyp_vcpu->vcpu.arch.vcpu_debug_state; + else if (kvm_host_owns_debug_regs(&hyp_vcpu->vcpu)) + host_vcpu->arch.external_debug_state = hyp_vcpu->vcpu.arch.external_debug_state; +} + static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) { struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu; fpsimd_sve_flush(); + flush_debug_state(hyp_vcpu); hyp_vcpu->vcpu.arch.ctxt = host_vcpu->arch.ctxt; @@ -123,6 +146,7 @@ static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) unsigned int i; fpsimd_sve_sync(&hyp_vcpu->vcpu); + sync_debug_state(hyp_vcpu); host_vcpu->arch.ctxt = hyp_vcpu->vcpu.arch.ctxt; -- cgit