From: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
To: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"peterz@infradead.org" <peterz@infradead.org>,
"keescook@chromium.org" <keescook@chromium.org>,
"Christopherson, Sean J" <sean.j.christopherson@intel.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"x86@kernel.org" <x86@kernel.org>,
"luto@kernel.org" <luto@kernel.org>,
"pbonzini@redhat.com" <pbonzini@redhat.com>,
"Hansen, Dave" <dave.hansen@intel.com>
Cc: "kristen@linux.intel.com" <kristen@linux.intel.com>,
"Dock, Deneen T" <deneen.t.dock@intel.com>
Subject: Re: [RFC PATCH 05/13] kvm: Add #PF injection for KVM XO
Date: Fri, 4 Oct 2019 19:11:16 +0000 [thread overview]
Message-ID: <99d2bf928d1971e7cacfcfa711e82aeac5186632.camel@intel.com> (raw)
In-Reply-To: <08e46327-7d98-5c63-58ba-e9a171790c25@redhat.com>
On Fri, 2019-10-04 at 09:42 +0200, Paolo Bonzini wrote:
> On 03/10/19 23:23, Rick Edgecombe wrote:
> > + if (!vcpu->arch.gva_available)
> > + return 0;
>
> Please return RET_PF_* constants, RET_PF_EMULATE here.
Ok.
> > + if (error_code & PFERR_WRITE_MASK)
> > + fault_error_code |= X86_PF_WRITE;
> > +
> > + fault.vector = PF_VECTOR;
> > + fault.error_code_valid = true;
> > + fault.error_code = fault_error_code;
> > + fault.nested_page_fault = false;
> > + fault.address = vcpu->arch.gva_val;
> > + fault.async_page_fault = true;
>
> Not an async page fault.
Right.
> > + kvm_inject_page_fault(vcpu, &fault);
> > +
> > + return 1;
>
> Here you would return RET_PF_RETRY - you've injected the page fault and
> all that's left to do is reenter execution of the vCPU.
>
> [...]
>
> > + if (unlikely(vcpu->arch.xo_fault)) {
> > + /*
> > + * If not enough information to inject the fault,
> > + * emulate to figure it out and emulate the PF.
> > + */
> > + if (!try_inject_exec_only_pf(vcpu, error_code))
> > + return RET_PF_EMULATE;
> > +
> > + return 1;
> > + }
>
> Returning 1 is wrong, it's also RET_PF_EMULATE. If you change
> try_inject_exec_only_pf return values to RET_PF_*, you can simply return
> the value of try_inject_exec_only_pf(vcpu, error_code).
Oh right! I must have broken this at some point. Thanks.
> That said, I wonder if it's better to just handle this in
> handle_ept_violation. Basically, if bits 5:3 of the exit qualification
> are 100 you can bypass the whole mmu.c page fault handling and just
> inject an exec-only page fault.
>
> Thanks,
>
> Paolo
Hmm, that could be cleaner. I'll see how it fits together when I fix the nested
case, since some of that logic looks to be in mmu.c.
Thanks,
Rick
next prev parent reply other threads:[~2019-10-04 19:11 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-03 21:23 [RFC PATCH 00/13] XOM for KVM guest userspace Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 01/13] kvm: Enable MTRR to work with GFNs with perm bits Rick Edgecombe
2019-10-14 6:47 ` Yu Zhang
2019-10-14 18:44 ` Edgecombe, Rick P
2019-10-03 21:23 ` [RFC PATCH 02/13] kvm: Add support for X86_FEATURE_KVM_XO Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 03/13] kvm: Add XO memslot type Rick Edgecombe
2019-10-04 7:27 ` Paolo Bonzini
2019-10-04 19:06 ` Edgecombe, Rick P
2019-10-06 16:15 ` Paolo Bonzini
2019-10-03 21:23 ` [RFC PATCH 04/13] kvm, vmx: Add support for gva exit qualification Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 05/13] kvm: Add #PF injection for KVM XO Rick Edgecombe
2019-10-04 7:42 ` Paolo Bonzini
2019-10-04 19:11 ` Edgecombe, Rick P [this message]
2019-10-03 21:23 ` [RFC PATCH 06/13] kvm: Add KVM_CAP_EXECONLY_MEM Rick Edgecombe
2019-10-04 7:24 ` Paolo Bonzini
2019-10-04 19:11 ` Edgecombe, Rick P
2019-10-03 21:23 ` [RFC PATCH 07/13] kvm: Add docs for KVM_CAP_EXECONLY_MEM Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 08/13] x86/boot: Rename USE_EARLY_PGTABLE_L5 Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 09/13] x86/cpufeature: Add detection of KVM XO Rick Edgecombe
2019-10-29 23:33 ` Kees Cook
2019-10-29 23:52 ` Edgecombe, Rick P
2019-10-30 14:55 ` Sean Christopherson
2019-10-30 21:02 ` Edgecombe, Rick P
2019-10-03 21:23 ` [RFC PATCH 10/13] x86/mm: Add NR page bit for " Rick Edgecombe
2019-10-04 7:33 ` Paolo Bonzini
2019-10-03 21:23 ` [RFC PATCH 11/13] x86, ptdump: Add NR bit to page table dump Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 12/13] mmap: Add XO support for KVM XO Rick Edgecombe
2019-10-04 7:34 ` Paolo Bonzini
2019-10-04 19:12 ` Edgecombe, Rick P
2019-10-03 21:24 ` [RFC PATCH 13/13] x86/Kconfig: Add Kconfig for KVM based XO Rick Edgecombe
2019-10-29 23:36 ` Kees Cook
2019-10-30 0:01 ` Edgecombe, Rick P
2019-10-30 18:36 ` Kees Cook
2019-10-04 7:22 ` [RFC PATCH 00/13] XOM for KVM guest userspace Paolo Bonzini
2019-10-04 19:03 ` Edgecombe, Rick P
2019-10-04 14:56 ` Andy Lutomirski
2019-10-04 20:09 ` Edgecombe, Rick P
2019-10-05 1:33 ` Andy Lutomirski
2019-10-07 18:14 ` Edgecombe, Rick P
2019-10-29 23:40 ` Kees Cook
2019-10-30 0:27 ` Edgecombe, Rick P
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