From: Maxim Levitsky <mlevitsk@redhat.com>
To: kvm@vger.kernel.org
Cc: Sean Christopherson <seanjc@google.com>,
x86@kernel.org, Kees Cook <keescook@chromium.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
linux-kernel@vger.kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Borislav Petkov <bp@alien8.de>, Joerg Roedel <joro@8bytes.org>,
Ingo Molnar <mingo@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>,
Maxim Levitsky <mlevitsk@redhat.com>
Subject: [PATCH v2 02/11] KVM: x86: emulator: introduce update_emulation_mode
Date: Tue, 21 Jun 2022 18:08:53 +0300 [thread overview]
Message-ID: <20220621150902.46126-3-mlevitsk@redhat.com> (raw)
In-Reply-To: <20220621150902.46126-1-mlevitsk@redhat.com>
Some instructions update the cpu execution mode, which needs
to update the emulation mode.
Extract this code, and make assign_eip_far use it.
assign_eip_far now reads CS, instead of getting it via a parameter,
which is ok, because callers always assign CS to the
same value before calling it.
No functional change is intended.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
arch/x86/kvm/emulate.c | 85 ++++++++++++++++++++++++++++--------------
1 file changed, 57 insertions(+), 28 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 5aeb343ca8b007..2c0087df2d7e6a 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -804,8 +804,7 @@ static int linearize(struct x86_emulate_ctxt *ctxt,
ctxt->mode, linear);
}
-static inline int assign_eip(struct x86_emulate_ctxt *ctxt, ulong dst,
- enum x86emul_mode mode)
+static inline int assign_eip(struct x86_emulate_ctxt *ctxt, ulong dst)
{
ulong linear;
int rc;
@@ -815,41 +814,71 @@ static inline int assign_eip(struct x86_emulate_ctxt *ctxt, ulong dst,
if (ctxt->op_bytes != sizeof(unsigned long))
addr.ea = dst & ((1UL << (ctxt->op_bytes << 3)) - 1);
- rc = __linearize(ctxt, addr, &max_size, 1, false, true, mode, &linear);
+ rc = __linearize(ctxt, addr, &max_size, 1, false, true, ctxt->mode, &linear);
if (rc == X86EMUL_CONTINUE)
ctxt->_eip = addr.ea;
return rc;
}
+static inline int update_emulation_mode(struct x86_emulate_ctxt *ctxt)
+{
+ u64 efer;
+ struct desc_struct cs;
+ u16 selector;
+ u32 base3;
+
+ ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
+
+ if (!ctxt->ops->get_cr(ctxt, 0) & X86_CR0_PE) {
+ /* Real mode. cpu must not have long mode active */
+ if (efer & EFER_LMA)
+ return X86EMUL_UNHANDLEABLE;
+ ctxt->mode = X86EMUL_MODE_REAL;
+ return X86EMUL_CONTINUE;
+ }
+
+ if (ctxt->eflags & X86_EFLAGS_VM) {
+ /* Protected/VM86 mode. cpu must not have long mode active */
+ if (efer & EFER_LMA)
+ return X86EMUL_UNHANDLEABLE;
+ ctxt->mode = X86EMUL_MODE_VM86;
+ return X86EMUL_CONTINUE;
+ }
+
+ if (!ctxt->ops->get_segment(ctxt, &selector, &cs, &base3, VCPU_SREG_CS))
+ return X86EMUL_UNHANDLEABLE;
+
+ if (efer & EFER_LMA) {
+ if (cs.l) {
+ /* Proper long mode */
+ ctxt->mode = X86EMUL_MODE_PROT64;
+ } else if (cs.d) {
+ /* 32 bit compatibility mode*/
+ ctxt->mode = X86EMUL_MODE_PROT32;
+ } else {
+ ctxt->mode = X86EMUL_MODE_PROT16;
+ }
+ } else {
+ /* Legacy 32 bit / 16 bit mode */
+ ctxt->mode = cs.d ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;
+ }
+
+ return X86EMUL_CONTINUE;
+}
+
static inline int assign_eip_near(struct x86_emulate_ctxt *ctxt, ulong dst)
{
- return assign_eip(ctxt, dst, ctxt->mode);
+ return assign_eip(ctxt, dst);
}
-static int assign_eip_far(struct x86_emulate_ctxt *ctxt, ulong dst,
- const struct desc_struct *cs_desc)
+static int assign_eip_far(struct x86_emulate_ctxt *ctxt, ulong dst)
{
- enum x86emul_mode mode = ctxt->mode;
- int rc;
+ int rc = update_emulation_mode(ctxt);
-#ifdef CONFIG_X86_64
- if (ctxt->mode >= X86EMUL_MODE_PROT16) {
- if (cs_desc->l) {
- u64 efer = 0;
+ if (rc != X86EMUL_CONTINUE)
+ return rc;
- ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
- if (efer & EFER_LMA)
- mode = X86EMUL_MODE_PROT64;
- } else
- mode = X86EMUL_MODE_PROT32; /* temporary value */
- }
-#endif
- if (mode == X86EMUL_MODE_PROT16 || mode == X86EMUL_MODE_PROT32)
- mode = cs_desc->d ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;
- rc = assign_eip(ctxt, dst, mode);
- if (rc == X86EMUL_CONTINUE)
- ctxt->mode = mode;
- return rc;
+ return assign_eip(ctxt, dst);
}
static inline int jmp_rel(struct x86_emulate_ctxt *ctxt, int rel)
@@ -2184,7 +2213,7 @@ static int em_jmp_far(struct x86_emulate_ctxt *ctxt)
if (rc != X86EMUL_CONTINUE)
return rc;
- rc = assign_eip_far(ctxt, ctxt->src.val, &new_desc);
+ rc = assign_eip_far(ctxt, ctxt->src.val);
/* Error handling is not implemented. */
if (rc != X86EMUL_CONTINUE)
return X86EMUL_UNHANDLEABLE;
@@ -2262,7 +2291,7 @@ static int em_ret_far(struct x86_emulate_ctxt *ctxt)
&new_desc);
if (rc != X86EMUL_CONTINUE)
return rc;
- rc = assign_eip_far(ctxt, eip, &new_desc);
+ rc = assign_eip_far(ctxt, eip);
/* Error handling is not implemented. */
if (rc != X86EMUL_CONTINUE)
return X86EMUL_UNHANDLEABLE;
@@ -3482,7 +3511,7 @@ static int em_call_far(struct x86_emulate_ctxt *ctxt)
if (rc != X86EMUL_CONTINUE)
return rc;
- rc = assign_eip_far(ctxt, ctxt->src.val, &new_desc);
+ rc = assign_eip_far(ctxt, ctxt->src.val);
if (rc != X86EMUL_CONTINUE)
goto fail;
--
2.26.3
next prev parent reply other threads:[~2022-06-21 15:09 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-21 15:08 [PATCH v2 00/11] SMM emulation and interrupt shadow fixes Maxim Levitsky
2022-06-21 15:08 ` [PATCH v2 01/11] KVM: x86: emulator: em_sysexit should update ctxt->mode Maxim Levitsky
2022-06-21 15:08 ` Maxim Levitsky [this message]
2022-07-20 23:44 ` [PATCH v2 02/11] KVM: x86: emulator: introduce update_emulation_mode Sean Christopherson
2022-07-21 11:52 ` Maxim Levitsky
2022-07-21 14:23 ` Sean Christopherson
2022-06-21 15:08 ` [PATCH v2 03/11] KVM: x86: emulator: remove assign_eip_near/far Maxim Levitsky
2022-07-20 23:51 ` Sean Christopherson
2022-07-21 11:52 ` Maxim Levitsky
2022-06-21 15:08 ` [PATCH v2 04/11] KVM: x86: emulator: update the emulation mode after rsm Maxim Levitsky
2022-06-21 15:08 ` [PATCH v2 05/11] KVM: x86: emulator: update the emulation mode after CR0 write Maxim Levitsky
2022-07-20 23:50 ` Sean Christopherson
2022-07-21 11:53 ` Maxim Levitsky
2022-07-21 14:11 ` Sean Christopherson
2022-07-21 14:57 ` Maxim Levitsky
2022-06-21 15:08 ` [PATCH v2 06/11] KVM: x86: emulator/smm: number of GPRs in the SMRAM image depends on the image format Maxim Levitsky
2022-07-21 0:06 ` Sean Christopherson
2022-07-21 0:09 ` Sean Christopherson
2022-06-21 15:08 ` [PATCH v2 07/11] KVM: x86: emulator/smm: add structs for KVM's smram layout Maxim Levitsky
2022-07-21 0:40 ` Sean Christopherson
2022-07-21 11:54 ` Maxim Levitsky
2022-06-21 15:08 ` [PATCH v2 08/11] KVM: x86: emulator/smm: use smram struct for 32 bit smram load/restore Maxim Levitsky
2022-06-21 15:09 ` [PATCH v2 09/11] KVM: x86: emulator/smm: use smram struct for 64 " Maxim Levitsky
2022-07-21 0:38 ` Sean Christopherson
2022-07-21 11:54 ` Maxim Levitsky
2022-06-21 15:09 ` [PATCH v2 10/11] KVM: x86: SVM: use smram structs Maxim Levitsky
2022-07-21 0:18 ` Sean Christopherson
2022-07-21 11:54 ` Maxim Levitsky
2022-07-21 0:39 ` Sean Christopherson
2022-07-21 11:54 ` Maxim Levitsky
2022-06-21 15:09 ` [PATCH v2 11/11] KVM: x86: emulator/smm: preserve interrupt shadow in SMRAM Maxim Levitsky
2022-06-29 16:31 ` Jim Mattson
2022-06-30 6:00 ` Maxim Levitsky
2022-06-30 16:00 ` Jim Mattson
2022-07-05 13:38 ` Maxim Levitsky
2022-07-05 13:40 ` Maxim Levitsky
2022-07-05 13:51 ` Maxim Levitsky
2022-07-06 18:13 ` Jim Mattson
2022-07-06 20:00 ` Maxim Levitsky
2022-07-06 20:38 ` Jim Mattson
2022-07-10 16:05 ` Maxim Levitsky
2022-06-29 7:21 ` [PATCH v2 00/11] SMM emulation and interrupt shadow fixes Maxim Levitsky
2022-07-14 11:06 ` Maxim Levitsky
2022-07-20 8:47 ` Maxim Levitsky
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