From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 10/13] KVM: x86: Shrink the usercopy region of the emulation context
Date: Mon, 2 Mar 2020 11:19:41 -0800 [thread overview]
Message-ID: <20200302191940.GD6244@linux.intel.com> (raw)
In-Reply-To: <727b8d16-2bab-6621-1f20-dc024ee65f10@redhat.com>
On Mon, Mar 02, 2020 at 07:40:27PM +0100, Paolo Bonzini wrote:
> On 26/02/20 18:51, Vitaly Kuznetsov wrote:
> >> +
> >> + /* Here begins the usercopy section. */
> >> + struct operand src;
> >> + struct operand src2;
> >> + struct operand dst;
> > Out of pure curiosity, how certain are we that this is going to be
> > enough for userspaces?
> >
>
> And also, where exactly are the user copies done?
Anything that funnels into ctxt->ops->read_std() or ctxt->ops->write_std(),
e.g.
if (ctxt->src2.type == OP_MEM) {
rc = segmented_read(ctxt, ctxt->src2.addr.mem,
&ctxt->src2.val, ctxt->src2.bytes);
if (rc != X86EMUL_CONTINUE)
goto done;
}
segmented_read() : @data = &ctxt->src2.val
|
|-> read_emulated()
|
|-> ctxt->ops->read_emulated() / emulator_read_emulated()
|
|-> emulator_read_write()
|
|-> emulator_read_write_onepage()
|
|-> ops->read_write_emulate() / read_emulate()
|
|-> kvm_vcpu_read_guest()
|
...
|-> __kvm_read_guest_page()
|
|-> __copy_from_user(data, ...)
next prev parent reply other threads:[~2020-03-02 19:19 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-18 23:29 [PATCH v2 00/13] KVM: x86: Allow userspace to disable the emulator Sean Christopherson
2020-02-18 23:29 ` [PATCH v2 01/13] KVM: x86: Refactor I/O emulation helpers to provide vcpu-only variant Sean Christopherson
2020-02-26 15:16 ` Vitaly Kuznetsov
2020-02-18 23:29 ` [PATCH v2 02/13] KVM: x86: Explicitly pass an exception struct to check_intercept Sean Christopherson
2020-02-18 23:29 ` [PATCH v2 03/13] KVM: x86: Move emulation-only helpers to emulate.c Sean Christopherson
2020-02-26 15:23 ` Vitaly Kuznetsov
2020-02-18 23:29 ` [PATCH v2 04/13] KVM: x86: Refactor R/W page helper to take the emulation context Sean Christopherson
2020-02-26 15:24 ` Vitaly Kuznetsov
2020-02-18 23:29 ` [PATCH v2 05/13] KVM: x86: Refactor emulated exception injection to take the emul context Sean Christopherson
2020-02-26 15:25 ` Vitaly Kuznetsov
2020-02-18 23:29 ` [PATCH v2 06/13] KVM: x86: Refactor emulate tracepoint to explicitly take context Sean Christopherson
2020-02-26 17:11 ` Vitaly Kuznetsov
2020-03-03 16:48 ` Sean Christopherson
2020-03-03 17:29 ` Paolo Bonzini
2020-03-03 17:42 ` Sean Christopherson
2020-03-03 17:44 ` Paolo Bonzini
2020-02-18 23:29 ` [PATCH v2 07/13] KVM: x86: Refactor init_emulate_ctxt() " Sean Christopherson
2020-02-26 17:13 ` Vitaly Kuznetsov
2020-02-18 23:29 ` [PATCH v2 08/13] KVM: x86: Dynamically allocate per-vCPU emulation context Sean Christopherson
2020-02-26 17:29 ` Vitaly Kuznetsov
2020-03-03 10:26 ` Paolo Bonzini
2020-03-03 14:57 ` Sean Christopherson
2020-03-03 16:18 ` Vitaly Kuznetsov
2020-03-03 16:52 ` Sean Christopherson
2020-02-18 23:29 ` [PATCH v2 09/13] KVM: x86: Move kvm_emulate.h into KVM's private directory Sean Christopherson
2020-02-26 17:38 ` Vitaly Kuznetsov
2020-03-03 10:27 ` Paolo Bonzini
2020-02-18 23:29 ` [PATCH v2 10/13] KVM: x86: Shrink the usercopy region of the emulation context Sean Christopherson
2020-02-26 17:51 ` Vitaly Kuznetsov
2020-03-02 18:40 ` Paolo Bonzini
2020-03-02 19:19 ` Sean Christopherson [this message]
2020-03-02 19:13 ` Sean Christopherson
2020-02-18 23:29 ` [PATCH v2 11/13] KVM: x86: Add helper to "handle" internal emulation error Sean Christopherson
2020-02-26 17:52 ` Vitaly Kuznetsov
2020-02-18 23:29 ` [PATCH v2 12/13] KVM: x86: Add variable to control existence of emulator Sean Christopherson
2020-02-26 18:01 ` Vitaly Kuznetsov
2020-02-18 23:29 ` [PATCH v2 13/13] KVM: x86: Allow userspace to disable the kernel's emulator Sean Christopherson
2020-03-02 18:42 ` [PATCH v2 00/13] KVM: x86: Allow userspace to disable the emulator Paolo Bonzini
2020-03-02 20:02 ` Sean Christopherson
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