From: Hou Wenlong <houwenlong93@linux.alibaba.com>
To: kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
"H. Peter Anvin" <hpa@zytor.com>,
linux-kernel@vger.kernel.org (open list:X86 ARCHITECTURE (32-BIT
AND 64-BIT))
Subject: [PATCH v2 3/3] kvm: x86: Emulate hypercall instead of fixing hypercall instruction
Date: Thu, 9 Sep 2021 19:55:25 +0800 [thread overview]
Message-ID: <7893d13e11648be0326834248fcb943088fb0b76.1631188011.git.houwenlong93@linux.alibaba.com> (raw)
In-Reply-To: <cover.1631188011.git.houwenlong93@linux.alibaba.com>
It is guest's resposibility to use right instruction for hypercall,
hypervisor could emulate wrong instruction instead of modifying
guest's instruction.
Signed-off-by: Hou Wenlong <houwenlong93@linux.alibaba.com>
---
arch/x86/kvm/emulate.c | 20 +++++++++-----------
arch/x86/kvm/kvm_emulate.h | 2 +-
arch/x86/kvm/x86.c | 17 ++++++++---------
3 files changed, 18 insertions(+), 21 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 2837110e66ed..671008a4ee20 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3732,13 +3732,11 @@ static int em_clts(struct x86_emulate_ctxt *ctxt)
static int em_hypercall(struct x86_emulate_ctxt *ctxt)
{
- int rc = ctxt->ops->fix_hypercall(ctxt);
+ int rc = ctxt->ops->hypercall(ctxt);
if (rc != X86EMUL_CONTINUE)
return rc;
- /* Let the processor re-execute the fixed hypercall */
- ctxt->_eip = ctxt->eip;
/* Disable writeback. */
ctxt->dst.type = OP_NONE;
return X86EMUL_CONTINUE;
@@ -4298,14 +4296,14 @@ static const struct opcode group7_rm2[] = {
};
static const struct opcode group7_rm3[] = {
- DIP(SrcNone | Prot | Priv, vmrun, check_svme_pa),
- II(SrcNone | Prot | EmulateOnUD, em_hypercall, vmmcall),
- DIP(SrcNone | Prot | Priv, vmload, check_svme_pa),
- DIP(SrcNone | Prot | Priv, vmsave, check_svme_pa),
- DIP(SrcNone | Prot | Priv, stgi, check_svme),
- DIP(SrcNone | Prot | Priv, clgi, check_svme),
- DIP(SrcNone | Prot | Priv, skinit, check_svme),
- DIP(SrcNone | Prot | Priv, invlpga, check_svme),
+ DIP(SrcNone | Prot | Priv, vmrun, check_svme_pa),
+ II(SrcNone | Prot | Priv | EmulateOnUD, em_hypercall, vmmcall),
+ DIP(SrcNone | Prot | Priv, vmload, check_svme_pa),
+ DIP(SrcNone | Prot | Priv, vmsave, check_svme_pa),
+ DIP(SrcNone | Prot | Priv, stgi, check_svme),
+ DIP(SrcNone | Prot | Priv, clgi, check_svme),
+ DIP(SrcNone | Prot | Priv, skinit, check_svme),
+ DIP(SrcNone | Prot | Priv, invlpga, check_svme),
};
static const struct opcode group7_rm7[] = {
diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
index 68b420289d7e..b090ec0688a6 100644
--- a/arch/x86/kvm/kvm_emulate.h
+++ b/arch/x86/kvm/kvm_emulate.h
@@ -216,7 +216,7 @@ struct x86_emulate_ops {
int (*read_pmc)(struct x86_emulate_ctxt *ctxt, u32 pmc, u64 *pdata);
void (*halt)(struct x86_emulate_ctxt *ctxt);
void (*wbinvd)(struct x86_emulate_ctxt *ctxt);
- int (*fix_hypercall)(struct x86_emulate_ctxt *ctxt);
+ int (*hypercall)(struct x86_emulate_ctxt *ctxt);
int (*intercept)(struct x86_emulate_ctxt *ctxt,
struct x86_instruction_info *info,
enum x86_intercept_stage stage);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b8d799e1c57c..aee3b08a1d85 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -329,7 +329,7 @@ static struct kmem_cache *kvm_alloc_emulator_cache(void)
size - useroffset, NULL);
}
-static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt);
+static int emulator_hypercall(struct x86_emulate_ctxt *ctxt);
static inline void kvm_async_pf_hash_reset(struct kvm_vcpu *vcpu)
{
@@ -7352,7 +7352,7 @@ static const struct x86_emulate_ops emulate_ops = {
.read_pmc = emulator_read_pmc,
.halt = emulator_halt,
.wbinvd = emulator_wbinvd,
- .fix_hypercall = emulator_fix_hypercall,
+ .hypercall = emulator_hypercall,
.intercept = emulator_intercept,
.get_cpuid = emulator_get_cpuid,
.guest_has_long_mode = emulator_guest_has_long_mode,
@@ -8747,16 +8747,15 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(kvm_emulate_hypercall);
-static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt)
+static int emulator_hypercall(struct x86_emulate_ctxt *ctxt)
{
+ int ret;
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
- char instruction[3];
- unsigned long rip = kvm_rip_read(vcpu);
-
- static_call(kvm_x86_patch_hypercall)(vcpu, instruction);
- return emulator_write_emulated(ctxt, rip, instruction, 3,
- &ctxt->exception);
+ ret = kvm_emulate_hypercall_noskip(vcpu);
+ if (ret)
+ return X86EMUL_CONTINUE;
+ return X86EMUL_IO_NEEDED;
}
static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu)
--
2.31.1
next prev parent reply other threads:[~2021-09-09 11:59 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1631188011.git.houwenlong93@linux.alibaba.com>
2021-09-09 11:55 ` [PATCH v2 1/3] kvm: x86: Introduce hypercall x86 ops for handling hypercall not in cpl0 Hou Wenlong
2021-09-09 16:39 ` Yu Zhang
2021-09-09 17:09 ` Sean Christopherson
2021-09-10 1:53 ` Yu Zhang
2021-09-09 11:55 ` [PATCH v2 2/3] kvm: x86: Refactor kvm_emulate_hypercall() to no skip instruction Hou Wenlong
2021-09-09 11:55 ` Hou Wenlong [this message]
2021-09-16 16:00 ` [PATCH v2 3/3] kvm: x86: Emulate hypercall instead of fixing hypercall instruction Sean Christopherson
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