From: Paolo Bonzini <pbonzini@redhat.com>
To: "Kyle Huey" <me@kylehuey.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, "Joerg Roedel" <joro@8bytes.org>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/5] KVM: VMX: Handle RFLAGS.TF in skip_emulated_instruction
Date: Mon, 28 Nov 2016 12:42:05 +0100 [thread overview]
Message-ID: <9eff6257-0420-102d-539a-d3b8b57ba05b@redhat.com> (raw)
In-Reply-To: <20161128041856.11420-6-khuey@kylehuey.com>
On 28/11/2016 05:18, Kyle Huey wrote:
> +
> + if (unlikely(vmx_get_rflags(vcpu) & X86_EFLAGS_TF)) {
> + if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
> + vcpu->run->debug.arch.dr6 = DR6_BS | DR6_FIXED_1 |
> + DR6_RTM;
> + vcpu->run->debug.arch.pc = vcpu->arch.singlestep_rip;
> + vcpu->run->debug.arch.exception = DB_VECTOR;
> + vcpu->run->exit_reason = KVM_EXIT_DEBUG;
> + return 0;
> + }
> +
> + /*
> + * "Certain debug exceptions may clear bit 0-3. The
> + * remaining contents of the DR6 register are never
> + * cleared by the processor".
> + */
> + vcpu->arch.dr6 &= ~15;
> + vcpu->arch.dr6 |= DR6_BS | DR6_RTM;
> + kvm_queue_exception(vcpu, DB_VECTOR);
> + }
This code is pretty much the same as kvm_vcpu_check_singlestep. Let's
not duplicate the code and implement skip_emulated_instruction can be
implemented in x86.c, like
unsigned long rflags = kvm_x86_ops->get_rflags(vcpu);
int r = EMULATE_DONE;
/* This would be the no_trap variant */
kvm_x86_ops->skip_emulated_instruction(vcpu);
kvm_vcpu_check_singlestep(vcpu, rflags, &r);
return r == EMULATE_DONE;
(because x86.c/vmx.c/svm.c are separate modules, when moving the function
to x86.c you should rename it to kvm_skip_emulated_instruction).
Paolo
next prev parent reply other threads:[~2016-11-28 11:42 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-28 4:18 [PATCH 0/5] KVM: VMX: Fix single stepping with emulated instructions Kyle Huey
2016-11-28 4:18 ` [PATCH 1/5] KVM: x86: Add a return value to kvm_emulate_cpuid Kyle Huey
2016-11-28 4:18 ` [PATCH 2/5] KVM: VMX: Reorder some skip_emulated_instruction calls Kyle Huey
2016-11-28 4:18 ` [PATCH 3/5] KVM: VMX: Move skip_emulated_instruction out of nested_vmx_check_vmcs12 Kyle Huey
2016-11-28 4:18 ` [PATCH 4/5] KVM: x86: Add a return value to skip_emulated_instruction and propagate it Kyle Huey
2016-11-28 4:18 ` [PATCH 5/5] KVM: VMX: Handle RFLAGS.TF in skip_emulated_instruction Kyle Huey
2016-11-28 11:42 ` Paolo Bonzini [this message]
2016-11-28 16:13 ` Kyle Huey
2016-11-28 17:19 ` Paolo Bonzini
2016-11-28 18:34 ` Kyle Huey
2016-11-28 22:43 ` Paolo Bonzini
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