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Diffstat (limited to 'arch/x86/kvm/svm.c')
-rw-r--r--arch/x86/kvm/svm.c121
1 files changed, 67 insertions, 54 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 7f4f9c2badae..ddf742768ecf 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -486,14 +486,14 @@ static int is_external_interrupt(u32 info)
return info == (SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_INTR);
}
-static u32 svm_get_interrupt_shadow(struct kvm_vcpu *vcpu, int mask)
+static u32 svm_get_interrupt_shadow(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
u32 ret = 0;
if (svm->vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK)
- ret |= KVM_X86_SHADOW_INT_STI | KVM_X86_SHADOW_INT_MOV_SS;
- return ret & mask;
+ ret = KVM_X86_SHADOW_INT_STI | KVM_X86_SHADOW_INT_MOV_SS;
+ return ret;
}
static void svm_set_interrupt_shadow(struct kvm_vcpu *vcpu, int mask)
@@ -1338,21 +1338,6 @@ static void svm_vcpu_put(struct kvm_vcpu *vcpu)
wrmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
}
-static void svm_update_cpl(struct kvm_vcpu *vcpu)
-{
- struct vcpu_svm *svm = to_svm(vcpu);
- int cpl;
-
- if (!is_protmode(vcpu))
- cpl = 0;
- else if (svm->vmcb->save.rflags & X86_EFLAGS_VM)
- cpl = 3;
- else
- cpl = svm->vmcb->save.cs.selector & 0x3;
-
- svm->vmcb->save.cpl = cpl;
-}
-
static unsigned long svm_get_rflags(struct kvm_vcpu *vcpu)
{
return to_svm(vcpu)->vmcb->save.rflags;
@@ -1360,11 +1345,12 @@ static unsigned long svm_get_rflags(struct kvm_vcpu *vcpu)
static void svm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
{
- unsigned long old_rflags = to_svm(vcpu)->vmcb->save.rflags;
-
+ /*
+ * Any change of EFLAGS.VM is accompained by a reload of SS
+ * (caused by either a task switch or an inter-privilege IRET),
+ * so we do not need to update the CPL here.
+ */
to_svm(vcpu)->vmcb->save.rflags = rflags;
- if ((old_rflags ^ rflags) & X86_EFLAGS_VM)
- svm_update_cpl(vcpu);
}
static void svm_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
@@ -1429,7 +1415,16 @@ static void svm_get_segment(struct kvm_vcpu *vcpu,
var->avl = (s->attrib >> SVM_SELECTOR_AVL_SHIFT) & 1;
var->l = (s->attrib >> SVM_SELECTOR_L_SHIFT) & 1;
var->db = (s->attrib >> SVM_SELECTOR_DB_SHIFT) & 1;
- var->g = (s->attrib >> SVM_SELECTOR_G_SHIFT) & 1;
+
+ /*
+ * AMD CPUs circa 2014 track the G bit for all segments except CS.
+ * However, the SVM spec states that the G bit is not observed by the
+ * CPU, and some VMware virtual CPUs drop the G bit for all segments.
+ * So let's synthesize a legal G bit for all segments, this helps
+ * running KVM nested. It also helps cross-vendor migration, because
+ * Intel's vmentry has a check on the 'G' bit.
+ */
+ var->g = s->limit > 0xfffff;
/*
* AMD's VMCB does not have an explicit unusable field, so emulate it
@@ -1438,14 +1433,6 @@ static void svm_get_segment(struct kvm_vcpu *vcpu,
var->unusable = !var->present || (var->type == 0);
switch (seg) {
- case VCPU_SREG_CS:
- /*
- * SVM always stores 0 for the 'G' bit in the CS selector in
- * the VMCB on a VMEXIT. This hurts cross-vendor migration:
- * Intel's VMENTRY has a check on the 'G' bit.
- */
- var->g = s->limit > 0xfffff;
- break;
case VCPU_SREG_TR:
/*
* Work around a bug where the busy flag in the tr selector
@@ -1476,6 +1463,7 @@ static void svm_get_segment(struct kvm_vcpu *vcpu,
*/
if (var->unusable)
var->db = 0;
+ var->dpl = to_svm(vcpu)->vmcb->save.cpl;
break;
}
}
@@ -1631,8 +1619,15 @@ static void svm_set_segment(struct kvm_vcpu *vcpu,
s->attrib |= (var->db & 1) << SVM_SELECTOR_DB_SHIFT;
s->attrib |= (var->g & 1) << SVM_SELECTOR_G_SHIFT;
}
- if (seg == VCPU_SREG_CS)
- svm_update_cpl(vcpu);
+
+ /*
+ * This is always accurate, except if SYSRET returned to a segment
+ * with SS.DPL != 3. Intel does not have this quirk, and always
+ * forces SS.DPL to 3 on sysret, so we ignore that case; fixing it
+ * would entail passing the CPL to userspace and back.
+ */
+ if (seg == VCPU_SREG_SS)
+ svm->vmcb->save.cpl = (s->attrib >> SVM_SELECTOR_DPL_SHIFT) & 3;
mark_dirty(svm->vmcb, VMCB_SEG);
}
@@ -2122,22 +2117,27 @@ static void nested_svm_unmap(struct page *page)
static int nested_svm_intercept_ioio(struct vcpu_svm *svm)
{
- unsigned port;
- u8 val, bit;
+ unsigned port, size, iopm_len;
+ u16 val, mask;
+ u8 start_bit;
u64 gpa;
if (!(svm->nested.intercept & (1ULL << INTERCEPT_IOIO_PROT)))
return NESTED_EXIT_HOST;
port = svm->vmcb->control.exit_info_1 >> 16;
+ size = (svm->vmcb->control.exit_info_1 & SVM_IOIO_SIZE_MASK) >>
+ SVM_IOIO_SIZE_SHIFT;
gpa = svm->nested.vmcb_iopm + (port / 8);
- bit = port % 8;
- val = 0;
+ start_bit = port % 8;
+ iopm_len = (start_bit + size > 8) ? 2 : 1;
+ mask = (0xf >> (4 - size)) << start_bit;
+ val = 0;
- if (kvm_read_guest(svm->vcpu.kvm, gpa, &val, 1))
- val &= (1 << bit);
+ if (kvm_read_guest(svm->vcpu.kvm, gpa, &val, iopm_len))
+ return NESTED_EXIT_DONE;
- return val ? NESTED_EXIT_DONE : NESTED_EXIT_HOST;
+ return (val & mask) ? NESTED_EXIT_DONE : NESTED_EXIT_HOST;
}
static int nested_svm_exit_handled_msr(struct vcpu_svm *svm)
@@ -2770,12 +2770,6 @@ static int xsetbv_interception(struct vcpu_svm *svm)
return 1;
}
-static int invalid_op_interception(struct vcpu_svm *svm)
-{
- kvm_queue_exception(&svm->vcpu, UD_VECTOR);
- return 1;
-}
-
static int task_switch_interception(struct vcpu_svm *svm)
{
u16 tss_selector;
@@ -3287,6 +3281,24 @@ static int pause_interception(struct vcpu_svm *svm)
return 1;
}
+static int nop_interception(struct vcpu_svm *svm)
+{
+ skip_emulated_instruction(&(svm->vcpu));
+ return 1;
+}
+
+static int monitor_interception(struct vcpu_svm *svm)
+{
+ printk_once(KERN_WARNING "kvm: MONITOR instruction emulated as NOP!\n");
+ return nop_interception(svm);
+}
+
+static int mwait_interception(struct vcpu_svm *svm)
+{
+ printk_once(KERN_WARNING "kvm: MWAIT instruction emulated as NOP!\n");
+ return nop_interception(svm);
+}
+
static int (*const svm_exit_handlers[])(struct vcpu_svm *svm) = {
[SVM_EXIT_READ_CR0] = cr_interception,
[SVM_EXIT_READ_CR3] = cr_interception,
@@ -3344,8 +3356,8 @@ static int (*const svm_exit_handlers[])(struct vcpu_svm *svm) = {
[SVM_EXIT_CLGI] = clgi_interception,
[SVM_EXIT_SKINIT] = skinit_interception,
[SVM_EXIT_WBINVD] = emulate_on_interception,
- [SVM_EXIT_MONITOR] = invalid_op_interception,
- [SVM_EXIT_MWAIT] = invalid_op_interception,
+ [SVM_EXIT_MONITOR] = monitor_interception,
+ [SVM_EXIT_MWAIT] = mwait_interception,
[SVM_EXIT_XSETBV] = xsetbv_interception,
[SVM_EXIT_NPF] = pf_interception,
};
@@ -4199,7 +4211,8 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu,
if (info->intercept == x86_intercept_cr_write)
icpt_info.exit_code += info->modrm_reg;
- if (icpt_info.exit_code != SVM_EXIT_WRITE_CR0)
+ if (icpt_info.exit_code != SVM_EXIT_WRITE_CR0 ||
+ info->intercept == x86_intercept_clts)
break;
intercept = svm->nested.intercept;
@@ -4244,14 +4257,14 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu,
u64 exit_info;
u32 bytes;
- exit_info = (vcpu->arch.regs[VCPU_REGS_RDX] & 0xffff) << 16;
-
if (info->intercept == x86_intercept_in ||
info->intercept == x86_intercept_ins) {
- exit_info |= SVM_IOIO_TYPE_MASK;
- bytes = info->src_bytes;
- } else {
+ exit_info = ((info->src_val & 0xffff) << 16) |
+ SVM_IOIO_TYPE_MASK;
bytes = info->dst_bytes;
+ } else {
+ exit_info = (info->dst_val & 0xffff) << 16;
+ bytes = info->src_bytes;
}
if (info->intercept == x86_intercept_outs ||
generated by cgit v1.2.3 (git 2.0.4) at 2025-12-13 04:54:52 +0000