From: Joerg Roedel <joro@8bytes.org>
To: Maxim Levitsky <mlevitsk@redhat.com>
Cc: kvm@vger.kernel.org, Vitaly Kuznetsov <vkuznets@redhat.com>,
linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Wanpeng Li <wanpengli@tencent.com>,
Kieran Bingham <kbingham@kernel.org>,
Jessica Yu <jeyu@kernel.org>, Jan Kiszka <jan.kiszka@siemens.com>,
Andrew Morton <akpm@linux-foundation.org>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>, Sean Christopherson <seanjc@google.com>,
Jim Mattson <jmattson@google.com>, Borislav Petkov <bp@alien8.de>,
Stefano Garzarella <sgarzare@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@suse.de>
Subject: Re: [PATCH 3/3] KVM: SVM: allow to intercept all exceptions for debug
Date: Tue, 16 Mar 2021 09:32:35 +0100 [thread overview]
Message-ID: <YFBtI55sVzIJ15U+@8bytes.org> (raw)
In-Reply-To: <20210315221020.661693-4-mlevitsk@redhat.com>
Hi Maxim,
On Tue, Mar 16, 2021 at 12:10:20AM +0200, Maxim Levitsky wrote:
> -static int (*const svm_exit_handlers[])(struct kvm_vcpu *vcpu) = {
> +static int (*svm_exit_handlers[])(struct kvm_vcpu *vcpu) = {
Can you keep this const and always set the necessary handlers? If
exceptions are not intercepted they will not be used.
> @@ -333,7 +334,9 @@ static inline void clr_exception_intercept(struct vcpu_svm *svm, u32 bit)
> struct vmcb *vmcb = svm->vmcb01.ptr;
>
> WARN_ON_ONCE(bit >= 32);
> - vmcb_clr_intercept(&vmcb->control, INTERCEPT_EXCEPTION_OFFSET + bit);
> +
> + if (!((1 << bit) & debug_intercept_exceptions))
> + vmcb_clr_intercept(&vmcb->control, INTERCEPT_EXCEPTION_OFFSET + bit);
This will break SEV-ES guests, as those will not cause an intercept but
now start to get #VC exceptions on every other exception that is raised.
SEV-ES guests are not prepared for that and will not even boot, so
please don't enable this feature for them.
next prev parent reply other threads:[~2021-03-16 8:33 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-15 22:10 [PATCH 0/3] KVM: my debug patch queue Maxim Levitsky
2021-03-15 22:10 ` [PATCH 1/3] scripts/gdb: rework lx-symbols gdb script Maxim Levitsky
2021-03-16 13:38 ` Jan Kiszka
2021-03-16 14:12 ` Maxim Levitsky
2021-03-15 22:10 ` [PATCH 2/3] KVM: x86: guest debug: don't inject interrupts while single stepping Maxim Levitsky
2021-03-15 23:37 ` Sean Christopherson
2021-03-16 9:16 ` Jan Kiszka
2021-03-16 10:59 ` Maxim Levitsky
2021-03-16 11:27 ` Jan Kiszka
2021-03-16 12:34 ` Maxim Levitsky
2021-03-16 13:46 ` Jan Kiszka
2021-03-16 14:34 ` Maxim Levitsky
2021-03-16 15:31 ` Jan Kiszka
[not found] ` <e2cd978e357155dbab21a523bb8981973bd10da7.camel@redhat.com>
2021-03-16 15:56 ` Jan Kiszka
2021-03-16 16:50 ` Sean Christopherson
2021-03-16 17:01 ` Jan Kiszka
2021-03-16 17:26 ` Sean Christopherson
2021-03-17 9:20 ` Jan Kiszka
2021-03-16 18:02 ` Maxim Levitsky
2021-03-18 16:02 ` Jan Kiszka
2021-03-18 12:21 ` Jan Kiszka
2021-03-16 10:55 ` Maxim Levitsky
2021-03-15 22:10 ` [PATCH 3/3] KVM: SVM: allow to intercept all exceptions for debug Maxim Levitsky
2021-03-16 8:32 ` Joerg Roedel [this message]
2021-03-16 10:51 ` Maxim Levitsky
2021-03-18 9:19 ` Joerg Roedel
2021-03-18 9:24 ` Maxim Levitsky
2021-03-18 15:47 ` Joerg Roedel
2021-03-18 16:35 ` Sean Christopherson
2021-03-18 16:41 ` Maxim Levitsky
2021-03-18 17:22 ` Sean Christopherson
2021-03-16 8:34 ` Borislav Petkov
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