From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Morse Subject: [PATCH 2/2] KVM: arm64: Restore host physical timer access on hyp_panic() Date: Tue, 25 Apr 2017 18:02:45 +0100 Message-ID: <20170425170245.4294-3-james.morse@arm.com> References: <20170425170245.4294-1-james.morse@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 44B2740C46 for ; Tue, 25 Apr 2017 13:01:02 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id LBrHnmPLYZjx for ; Tue, 25 Apr 2017 13:01:01 -0400 (EDT) Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 8F2CF40C8B for ; Tue, 25 Apr 2017 13:01:01 -0400 (EDT) In-Reply-To: <20170425170245.4294-1-james.morse@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: kvmarm@lists.cs.columbia.edu Cc: Marc Zyngier List-Id: kvmarm@lists.cs.columbia.edu When KVM panics, it hurridly restores the host context and parachutes into the host's panic() code. At some point panic() touches the physical timer/counter. Unless we are an arm64 system with VHE, this traps back to EL2. If we're lucky, we panic again. Add a __timer_save_state() call to KVMs hyp_panic() path, this saves the guest registers and disables the traps for the host. Fixes: 53fd5b6487e4 ("arm64: KVM: Add panic handling") Signed-off-by: James Morse --- arch/arm64/kvm/hyp/switch.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index aede1658aeda..e5f089de6526 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -422,6 +422,7 @@ void __hyp_text __noreturn __hyp_panic(void) vcpu = (struct kvm_vcpu *)read_sysreg(tpidr_el2); host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); + __timer_save_state(vcpu); __deactivate_traps(vcpu); __deactivate_vm(vcpu); __sysreg_restore_host_state(host_ctxt); -- 2.10.1