From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Paolo Bonzini <pbonzini@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 v2 10/13] KVM: x86: Shrink the usercopy region of the emulation context
Date: Tue, 18 Feb 2020 15:29:50 -0800 [thread overview]
Message-ID: <20200218232953.5724-11-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20200218232953.5724-1-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 2f0a600efdff..82f712d5c692 100644
--- a/arch/x86/kvm/kvm_emulate.h
+++ b/arch/x86/kvm/kvm_emulate.h
@@ -322,9 +322,6 @@ 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);
/*
@@ -349,6 +346,11 @@ 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 370af9fe0f5b..e1eaca65756b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -235,13 +235,13 @@ 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);
--
2.24.1
next prev parent reply other threads:[~2020-02-18 23:30 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 ` Sean Christopherson [this message]
2020-02-26 17:51 ` [PATCH v2 10/13] KVM: x86: Shrink the usercopy region of the emulation context Vitaly Kuznetsov
2020-03-02 18:40 ` Paolo Bonzini
2020-03-02 19:19 ` Sean Christopherson
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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