From: Sean Christopherson <sean.j.christopherson@intel.com>
To: "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
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: [PATCH 10/13] KVM: x86: Shrink the usercopy region of the emulation context
Date: Fri, 22 Nov 2019 14:39:56 -0800 [thread overview]
Message-ID: <20191122223959.13545-11-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20191122223959.13545-1-sean.j.christopherson@intel.com>
Shuffle a few operand structs to the end of struct x86_emulate_ctxt and
update the cache creation to whitelist only the region of the emulation
context that is expected to be copied to/from user memory, e.g. the
instruction operands, registers, and fetch/io/mem caches.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/kvm_emulate.h | 8 +++++---
arch/x86/kvm/x86.c | 12 ++++++------
2 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
index 844e833609db..c25133080666 100644
--- a/arch/x86/kvm/kvm_emulate.h
+++ b/arch/x86/kvm/kvm_emulate.h
@@ -318,9 +318,6 @@ struct x86_emulate_ctxt {
u8 intercept;
u8 op_bytes;
u8 ad_bytes;
- struct operand src;
- struct operand src2;
- struct operand dst;
int (*execute)(struct x86_emulate_ctxt *ctxt);
int (*check_perm)(struct x86_emulate_ctxt *ctxt);
/*
@@ -345,6 +342,11 @@ struct x86_emulate_ctxt {
u8 seg_override;
u64 d;
unsigned long _eip;
+
+ /* Here begins the usercopy section. */
+ struct operand src;
+ struct operand src2;
+ struct operand dst;
struct operand memop;
/* Fields above regs are cleared together. */
unsigned long _regs[NR_VCPU_REGS];
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 548cf3b659f5..418717876ad0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -231,13 +231,13 @@ static struct kmem_cache *x86_emulator_cache;
static struct kmem_cache *kvm_alloc_emulator_cache(void)
{
- return kmem_cache_create_usercopy("x86_emulator",
- sizeof(struct x86_emulate_ctxt),
+ unsigned int useroffset = offsetof(struct x86_emulate_ctxt, src);
+ unsigned int size = sizeof(struct x86_emulate_ctxt);
+
+ return kmem_cache_create_usercopy("x86_emulator", size,
__alignof__(struct x86_emulate_ctxt),
- SLAB_ACCOUNT,
- 0,
- sizeof(struct x86_emulate_ctxt),
- NULL);
+ SLAB_ACCOUNT, useroffset,
+ size - useroffset, NULL);
}
static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt);
--
2.24.0
next prev parent reply other threads:[~2019-11-22 22:40 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-22 22:39 [PATCH 00/13] KVM: x86: Allow userspace to disable the emulator Sean Christopherson
2019-11-22 22:39 ` [PATCH 01/13] KVM: x86: Refactor I/O emulation helpers to provide vcpu-only variant Sean Christopherson
2019-11-22 22:39 ` [PATCH 02/13] KVM: x86: Explicitly pass an exception struct to check_intercept Sean Christopherson
2019-11-22 22:39 ` [PATCH 03/13] KVM: x86: Move emulation-only helpers to emulate.c Sean Christopherson
2019-11-22 22:39 ` [PATCH 04/13] KVM: x86: Refactor R/W page helper to take the emulation context Sean Christopherson
2019-11-22 22:39 ` [PATCH 05/13] KVM: x86: Refactor emulated exception injection to take the emul context Sean Christopherson
2019-11-22 22:39 ` [PATCH 06/13] KVM: x86: Refactor emulate tracepoint to explicitly take context Sean Christopherson
2019-11-22 22:39 ` [PATCH 07/13] KVM: x86: Refactor init_emulate_ctxt() " Sean Christopherson
2019-11-22 22:39 ` [PATCH 08/13] KVM: x86: Dynamically allocate per-vCPU emulation context Sean Christopherson
2019-11-22 22:39 ` [PATCH 09/13] KVM: x86: Move kvm_emulate.h into KVM's private directory Sean Christopherson
2019-11-22 22:39 ` Sean Christopherson [this message]
2019-11-22 22:39 ` [PATCH 11/13] KVM: x86: Add helper to "handle" internal emulation error Sean Christopherson
2019-11-22 22:39 ` [PATCH 12/13] KVM: x86: Add variable to control existence of emulator Sean Christopherson
2019-11-22 22:39 ` [PATCH 13/13] KVM: x86: Allow userspace to disable the kernel's emulator Sean Christopherson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191122223959.13545-11-sean.j.christopherson@intel.com \
--to=sean.j.christopherson@intel.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=rkrcmar@redhat.com \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).