From 0067df413bd9d7e9ee3a78ece1e1a93535378862 Mon Sep 17 00:00:00 2001 From: James Morse Date: Mon, 15 Jan 2018 19:39:05 +0000 Subject: KVM: arm64: Handle RAS SErrors from EL2 on guest exit We expect to have firmware-first handling of RAS SErrors, with errors notified via an APEI method. For systems without firmware-first, add some minimal handling to KVM. There are two ways KVM can take an SError due to a guest, either may be a RAS error: we exit the guest due to an SError routed to EL2 by HCR_EL2.AMO, or we take an SError from EL2 when we unmask PSTATE.A from __guest_exit. The current SError from EL2 code unmasks SError and tries to fence any pending SError into a single instruction window. It then leaves SError unmasked. With the v8.2 RAS Extensions we may take an SError for a 'corrected' error, but KVM is only able to handle SError from EL2 if they occur during this single instruction window... The RAS Extensions give us a new instruction to synchronise and consume SErrors. The RAS Extensions document (ARM DDI0587), '2.4.1 ESB and Unrecoverable errors' describes ESB as synchronising SError interrupts generated by 'instructions, translation table walks, hardware updates to the translation tables, and instruction fetches on the same PE'. This makes ESB equivalent to KVMs existing 'dsb, mrs-daifclr, isb' sequence. Use the alternatives to synchronise and consume any SError using ESB instead of unmasking and taking the SError. Set ARM_EXIT_WITH_SERROR_BIT in the exit_code so that we can restart the vcpu if it turns out this SError has no impact on the vcpu. Reviewed-by: Marc Zyngier Signed-off-by: James Morse Signed-off-by: Catalin Marinas --- arch/arm64/kernel/asm-offsets.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm64/kernel/asm-offsets.c') diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 1dcc493f5765..1303e04110cd 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -132,6 +132,7 @@ int main(void) BLANK(); #ifdef CONFIG_KVM_ARM_HOST DEFINE(VCPU_CONTEXT, offsetof(struct kvm_vcpu, arch.ctxt)); + DEFINE(VCPU_FAULT_DISR, offsetof(struct kvm_vcpu, arch.fault.disr_el1)); DEFINE(CPU_GP_REGS, offsetof(struct kvm_cpu_context, gp_regs)); DEFINE(CPU_USER_PT_REGS, offsetof(struct kvm_regs, regs)); DEFINE(CPU_FP_REGS, offsetof(struct kvm_regs, fp_regs)); -- cgit v1.2.3