From 44636f976f5bb92631f0dd5fd26547d64c2c6a80 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Sep 2016 14:02:00 +0100 Subject: [PATCH] arm64: KVM: Preserve pending vSError in world switch The HCR_EL2.VSE bit is used to signal an SError to a guest, and has the peculiar feature of getting cleared when the guest has taken the abort (this is the only bit that behaves as such in this register). This means that if we signal such an abort, we must leave it in the guest context until it disappears from HCR_EL2, and at which point it must be cleared from the context. This is achieved by reading back from HCR_EL2 until the guest takes the fault. Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm64/kvm/hyp/switch.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index b3a66c50d12b..8246de27ace1 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -110,6 +110,15 @@ static hyp_alternate_select(__deactivate_traps_arch, static void __hyp_text __deactivate_traps(struct kvm_vcpu *vcpu) { + /* + * If we pended a virtual abort, preserve it until it gets + * cleared. See D1.14.3 (Virtual Interrupts) for details, but + * the crucial bit is "On taking a vSError interrupt, + * HCR_EL2.VSE is cleared to 0." + */ + if (vcpu->arch.hcr_el2 & HCR_VSE) + vcpu->arch.hcr_el2 = read_sysreg(hcr_el2); + __deactivate_traps_arch()(); write_sysreg(0, hstr_el2); write_sysreg(read_sysreg(mdcr_el2) & MDCR_EL2_HPMN_MASK, mdcr_el2); -- 2.20.1