kvm_complete_insn_gp is a nice little function that dates back to more
than 10 years ago but was almost never used.
This simple series continues what was done for RDMSR/WRMSR in preparation
for SEV-ES support, using it in XSETBV, INVPCID and MOV to DR intercepts.
Paolo
Paolo Bonzini (3):
KVM: x86: move kvm_inject_gp up from kvm_set_xcr to callers
KVM: x86: move kvm_inject_gp up from kvm_handle_invpcid to callers
KVM: x86: move kvm_inject_gp up from kvm_set_dr to callers
arch/x86/kvm/svm/svm.c | 32 +++++++++++++++-----------------
arch/x86/kvm/vmx/vmx.c | 35 ++++++++++++++++++-----------------
arch/x86/kvm/x86.c | 38 ++++++++++++--------------------------
3 files changed, 45 insertions(+), 60 deletions(-)
--
2.26.2
>From 54473e9148b13418d827019dcc70fa379e5458fb Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonz...@redhat.com>
Date: Mon, 14 Dec 2020 07:49:54 -0500
Subject: [PATCH 1/3] KVM: x86: move kvm_inject_gp up from kvm_set_xcr to
callers
Push the injection of #GP up to the callers, so that they can just use
kvm_complete_insn_gp.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
arch/x86/kvm/svm/svm.c | 7 ++-----
arch/x86/kvm/vmx/vmx.c | 5 ++---
arch/x86/kvm/x86.c | 10 ++++------
3 files changed, 8 insertions(+), 14 deletions(-)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 687876211ebe..65d70b9691b4 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2337,11 +2337,8 @@ static int xsetbv_interception(struct vcpu_svm *svm)
u64 new_bv = kvm_read_edx_eax(&svm->vcpu);
u32 index = kvm_rcx_read(&svm->vcpu);
- if (kvm_set_xcr(&svm->vcpu, index, new_bv) == 0) {
- return kvm_skip_emulated_instruction(&svm->vcpu);
- }
-
- return 1;
+ int err = kvm_set_xcr(&svm->vcpu, index, new_bv);
+ return kvm_complete_insn_gp(&svm->vcpu, err);
}
static int rdpru_interception(struct vcpu_svm *svm)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 9986a59f71a4..28daceb4f70d 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5227,9 +5227,8 @@ static int handle_xsetbv(struct kvm_vcpu *vcpu)
u64 new_bv = kvm_read_edx_eax(vcpu);
u32 index = kvm_rcx_read(vcpu);
- if (kvm_set_xcr(vcpu, index, new_bv) == 0)
- return kvm_skip_emulated_instruction(vcpu);
- return 1;
+ int err = kvm_set_xcr(vcpu, index, new_bv);
+ return kvm_complete_insn_gp(vcpu, err);
}
static int handle_apic_access(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d14230dd38d8..08568c47337c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -986,12 +986,10 @@ static int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32
index, u64 xcr)
int kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
{
- if (static_call(kvm_x86_get_cpl)(vcpu) != 0 ||
- __kvm_set_xcr(vcpu, index, xcr)) {
- kvm_inject_gp(vcpu, 0);
- return 1;
- }
- return 0;
+ if (static_call(kvm_x86_get_cpl)(vcpu) == 0)
+ return __kvm_set_xcr(vcpu, index, xcr);
+
+ return 1;
}
EXPORT_SYMBOL_GPL(kvm_set_xcr);
--
2.26.2
>From 3433aae8a0ecf04478e9bf2a6df5f66b4aefe254 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonz...@redhat.com>
Date: Mon, 14 Dec 2020 07:49:54 -0500
Subject: [PATCH 2/3] KVM: x86: move kvm_inject_gp up from kvm_handle_invpcid
to callers
Push the injection of #GP up to the callers, so that they can just use
kvm_complete_insn_gp.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
arch/x86/kvm/svm/svm.c | 11 ++++++-----
arch/x86/kvm/vmx/vmx.c | 11 ++++++-----
arch/x86/kvm/x86.c | 9 +++------
3 files changed, 15 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 65d70b9691b4..c0d41a6920f0 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3057,6 +3057,7 @@ static int invpcid_interception(struct vcpu_svm *svm)
struct kvm_vcpu *vcpu = &svm->vcpu;
unsigned long type;
gva_t gva;
+ int err;
if (!guest_cpuid_has(vcpu, X86_FEATURE_INVPCID)) {
kvm_queue_exception(vcpu, UD_VECTOR);
@@ -3071,12 +3072,12 @@ static int invpcid_interception(struct vcpu_svm *svm)
type = svm->vmcb->control.exit_info_2;
gva = svm->vmcb->control.exit_info_1;
- if (type > 3) {
- kvm_inject_gp(vcpu, 0);
- return 1;
- }
+ if (type > 3)
+ err = 1;
+ else
+ err = kvm_handle_invpcid(vcpu, type, gva);
- return kvm_handle_invpcid(vcpu, type, gva);
+ return kvm_complete_insn_gp(&svm->vcpu, err);
}
static int (*const svm_exit_handlers[])(struct vcpu_svm *svm) = {
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 28daceb4f70d..a07fce6d0bbb 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5559,6 +5559,7 @@ static int handle_invpcid(struct kvm_vcpu *vcpu)
u64 pcid;
u64 gla;
} operand;
+ int err = 1;
if (!guest_cpuid_has(vcpu, X86_FEATURE_INVPCID)) {
kvm_queue_exception(vcpu, UD_VECTOR);
@@ -5568,10 +5569,8 @@ static int handle_invpcid(struct kvm_vcpu *vcpu)
vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
type = kvm_register_readl(vcpu, (vmx_instruction_info >> 28) & 0xf);
- if (type > 3) {
- kvm_inject_gp(vcpu, 0);
- return 1;
- }
+ if (type > 3)
+ goto out;
/* According to the Intel instruction reference, the memory operand
* is read even if it isn't needed (e.g., for type==all)
@@ -5581,7 +5580,9 @@ static int handle_invpcid(struct kvm_vcpu *vcpu)
sizeof(operand), &gva))
return 1;
- return kvm_handle_invpcid(vcpu, type, gva);
+ err = kvm_handle_invpcid(vcpu, type, gva);
+out:
+ return kvm_complete_insn_gp(vcpu, err);
}
static int handle_pml_full(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 08568c47337c..edbeb162012b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11375,7 +11375,6 @@ int kvm_handle_invpcid(struct kvm_vcpu *vcpu, unsigned
long type, gva_t gva)
return kvm_handle_memory_failure(vcpu, r, &e);
if (operand.pcid >> 12 != 0) {
- kvm_inject_gp(vcpu, 0);
return 1;
}
@@ -11385,15 +11384,13 @@ int kvm_handle_invpcid(struct kvm_vcpu *vcpu,
unsigned long type, gva_t gva)
case INVPCID_TYPE_INDIV_ADDR:
if ((!pcid_enabled && (operand.pcid != 0)) ||
is_noncanonical_address(operand.gla, vcpu)) {
- kvm_inject_gp(vcpu, 0);
return 1;
}
kvm_mmu_invpcid_gva(vcpu, operand.gla, operand.pcid);
- return kvm_skip_emulated_instruction(vcpu);
+ return 0;
case INVPCID_TYPE_SINGLE_CTXT:
if (!pcid_enabled && (operand.pcid != 0)) {
- kvm_inject_gp(vcpu, 0);
return 1;
}
@@ -11414,7 +11411,7 @@ int kvm_handle_invpcid(struct kvm_vcpu *vcpu, unsigned
long type, gva_t gva)
* resync will happen anyway before switching to any other CR3.
*/
- return kvm_skip_emulated_instruction(vcpu);
+ return 0;
case INVPCID_TYPE_ALL_NON_GLOBAL:
/*
@@ -11427,7 +11424,7 @@ int kvm_handle_invpcid(struct kvm_vcpu *vcpu, unsigned
long type, gva_t gva)
fallthrough;
case INVPCID_TYPE_ALL_INCL_GLOBAL:
kvm_mmu_unload(vcpu);
- return kvm_skip_emulated_instruction(vcpu);
+ return 0;
default:
BUG(); /* We have already checked above that type <= 3 */
--
2.26.2
>From 010ddc679488a7f65d16f5b6674f2ad20d65adf7 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonz...@redhat.com>
Date: Mon, 14 Dec 2020 07:49:54 -0500
Subject: [PATCH 3/3] KVM: x86: move kvm_inject_gp up from kvm_set_dr to
callers
Push the injection of #GP up to the callers, so that they can just use
kvm_complete_insn_gp. __kvm_set_dr is pretty much what the callers can use
together with kvm_complete_insn_gp, so rename it to kvm_set_dr and drop
the old kvm_set_dr wrapper.
This allows nested VMX code, which really wanted to use __kvm_set_dr, to
use the right function.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
arch/x86/kvm/svm/svm.c | 14 +++++++-------
arch/x86/kvm/vmx/vmx.c | 19 ++++++++++---------
arch/x86/kvm/x86.c | 19 +++++--------------
3 files changed, 22 insertions(+), 30 deletions(-)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index c0d41a6920f0..818cf3babef2 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2599,6 +2599,7 @@ static int dr_interception(struct vcpu_svm *svm)
{
int reg, dr;
unsigned long val;
+ int err;
if (svm->vcpu.guest_debug == 0) {
/*
@@ -2617,19 +2618,18 @@ static int dr_interception(struct vcpu_svm *svm)
reg = svm->vmcb->control.exit_info_1 & SVM_EXITINFO_REG_MASK;
dr = svm->vmcb->control.exit_code - SVM_EXIT_READ_DR0;
+ if (!kvm_require_dr(&svm->vcpu, dr & 15))
+ return 1;
+
if (dr >= 16) { /* mov to DRn */
- if (!kvm_require_dr(&svm->vcpu, dr - 16))
- return 1;
val = kvm_register_read(&svm->vcpu, reg);
- kvm_set_dr(&svm->vcpu, dr - 16, val);
+ err = kvm_set_dr(&svm->vcpu, dr - 16, val);
} else {
- if (!kvm_require_dr(&svm->vcpu, dr))
- return 1;
- kvm_get_dr(&svm->vcpu, dr, &val);
+ err = kvm_get_dr(&svm->vcpu, dr, &val);
kvm_register_write(&svm->vcpu, reg, val);
}
- return kvm_skip_emulated_instruction(&svm->vcpu);
+ return kvm_complete_insn_gp(&svm->vcpu, err);
}
static int cr8_write_interception(struct vcpu_svm *svm)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index a07fce6d0bbb..41a26d98fb95 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5099,6 +5099,7 @@ static int handle_dr(struct kvm_vcpu *vcpu)
{
unsigned long exit_qualification;
int dr, dr7, reg;
+ int err = 1;
exit_qualification = vmx_get_exit_qual(vcpu);
dr = exit_qualification & DEBUG_REG_ACCESS_NUM;
@@ -5107,9 +5108,9 @@ static int handle_dr(struct kvm_vcpu *vcpu)
if (!kvm_require_dr(vcpu, dr))
return 1;
- /* Do not handle if the CPL > 0, will trigger GP on re-entry */
- if (!kvm_require_cpl(vcpu, 0))
- return 1;
+ if (kvm_x86_ops.get_cpl(vcpu) > 0)
+ goto out;
+
dr7 = vmcs_readl(GUEST_DR7);
if (dr7 & DR7_GD) {
/*
@@ -5146,14 +5147,14 @@ static int handle_dr(struct kvm_vcpu *vcpu)
if (exit_qualification & TYPE_MOV_FROM_DR) {
unsigned long val;
- if (kvm_get_dr(vcpu, dr, &val))
- return 1;
+ err = kvm_get_dr(vcpu, dr, &val);
kvm_register_write(vcpu, reg, val);
- } else
- if (kvm_set_dr(vcpu, dr, kvm_register_readl(vcpu, reg)))
- return 1;
+ } else {
+ err = kvm_set_dr(vcpu, dr, kvm_register_readl(vcpu, reg));
+ }
- return kvm_skip_emulated_instruction(vcpu);
+out:
+ return kvm_complete_insn_gp(vcpu, err);
}
static void vmx_sync_dirty_debug_regs(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index edbeb162012b..b748bf0d6d33 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1147,7 +1147,7 @@ static u64 kvm_dr6_fixed(struct kvm_vcpu *vcpu)
return fixed;
}
-static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
+int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
{
size_t size = ARRAY_SIZE(vcpu->arch.db);
@@ -1160,13 +1160,13 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr,
unsigned long val)
case 4:
case 6:
if (!kvm_dr6_valid(val))
- return -1; /* #GP */
+ return 1; /* #GP */
vcpu->arch.dr6 = (val & DR6_VOLATILE) | kvm_dr6_fixed(vcpu);
break;
case 5:
default: /* 7 */
if (!kvm_dr7_valid(val))
- return -1; /* #GP */
+ return 1; /* #GP */
vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1;
kvm_update_dr7(vcpu);
break;
@@ -1174,15 +1174,6 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr,
unsigned long val)
return 0;
}
-
-int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
-{
- if (__kvm_set_dr(vcpu, dr, val)) {
- kvm_inject_gp(vcpu, 0);
- return 1;
- }
- return 0;
-}
EXPORT_SYMBOL_GPL(kvm_set_dr);
int kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
@@ -6595,7 +6586,7 @@ static int emulator_set_dr(struct x86_emulate_ctxt *ctxt,
int dr,
unsigned long value)
{
- return __kvm_set_dr(emul_to_vcpu(ctxt), dr, value);
+ return kvm_set_dr(emul_to_vcpu(ctxt), dr, value);
}
static u64 mk_cr_64(u64 curr_cr, u32 new_val)
@@ -8636,7 +8627,7 @@ static void enter_smm(struct kvm_vcpu *vcpu)
dt.address = dt.size = 0;
static_call(kvm_x86_set_idt)(vcpu, &dt);
- __kvm_set_dr(vcpu, 7, DR7_FIXED_1);
+ kvm_set_dr(vcpu, 7, DR7_FIXED_1);
cs.selector = (vcpu->arch.smbase >> 4) & 0xffff;
cs.base = vcpu->arch.smbase;
--
2.26.2
