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-rw-r--r--arch/x86/kvm/vmx/vmenter.S8
-rw-r--r--arch/x86/kvm/vmx/vmx.c62
-rw-r--r--arch/x86/kvm/vmx/vmx_ops.h12
3 files changed, 59 insertions, 23 deletions
diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S
index 07e927d4d099..be275a0410a8 100644
--- a/arch/x86/kvm/vmx/vmenter.S
+++ b/arch/x86/kvm/vmx/vmenter.S
@@ -303,10 +303,8 @@ SYM_FUNC_START(vmx_do_nmi_irqoff)
VMX_DO_EVENT_IRQOFF call asm_exc_nmi_kvm_vmx
SYM_FUNC_END(vmx_do_nmi_irqoff)
-
-.section .text, "ax"
-
#ifndef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
+
/**
* vmread_error_trampoline - Trampoline from inline asm to vmread_error()
* @field: VMCS field encoding that failed
@@ -335,7 +333,7 @@ SYM_FUNC_START(vmread_error_trampoline)
mov 3*WORD_SIZE(%_ASM_BP), %_ASM_ARG2
mov 2*WORD_SIZE(%_ASM_BP), %_ASM_ARG1
- call vmread_error
+ call vmread_error_trampoline2
/* Zero out @fault, which will be popped into the result register. */
_ASM_MOV $0, 3*WORD_SIZE(%_ASM_BP)
@@ -357,6 +355,8 @@ SYM_FUNC_START(vmread_error_trampoline)
SYM_FUNC_END(vmread_error_trampoline)
#endif
+.section .text, "ax"
+
SYM_FUNC_START(vmx_do_interrupt_irqoff)
VMX_DO_EVENT_IRQOFF CALL_NOSPEC _ASM_ARG1
SYM_FUNC_END(vmx_do_interrupt_irqoff)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 0ecf4be2c6af..df461f387e20 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -441,13 +441,23 @@ do { \
pr_warn_ratelimited(fmt); \
} while (0)
-void vmread_error(unsigned long field, bool fault)
+noinline void vmread_error(unsigned long field)
{
- if (fault)
+ vmx_insn_failed("vmread failed: field=%lx\n", field);
+}
+
+#ifndef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
+noinstr void vmread_error_trampoline2(unsigned long field, bool fault)
+{
+ if (fault) {
kvm_spurious_fault();
- else
- vmx_insn_failed("vmread failed: field=%lx\n", field);
+ } else {
+ instrumentation_begin();
+ vmread_error(field);
+ instrumentation_end();
+ }
}
+#endif
noinline void vmwrite_error(unsigned long field, unsigned long value)
{
@@ -1503,6 +1513,11 @@ void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
struct vcpu_vmx *vmx = to_vmx(vcpu);
unsigned long old_rflags;
+ /*
+ * Unlike CR0 and CR4, RFLAGS handling requires checking if the vCPU
+ * is an unrestricted guest in order to mark L2 as needing emulation
+ * if L1 runs L2 as a restricted guest.
+ */
if (is_unrestricted_guest(vcpu)) {
kvm_register_mark_available(vcpu, VCPU_EXREG_RFLAGS);
vmx->rflags = rflags;
@@ -3037,6 +3052,15 @@ static void enter_rmode(struct kvm_vcpu *vcpu)
struct vcpu_vmx *vmx = to_vmx(vcpu);
struct kvm_vmx *kvm_vmx = to_kvm_vmx(vcpu->kvm);
+ /*
+ * KVM should never use VM86 to virtualize Real Mode when L2 is active,
+ * as using VM86 is unnecessary if unrestricted guest is enabled, and
+ * if unrestricted guest is disabled, VM-Enter (from L1) with CR0.PG=0
+ * should VM-Fail and KVM should reject userspace attempts to stuff
+ * CR0.PG=0 when L2 is active.
+ */
+ WARN_ON_ONCE(is_guest_mode(vcpu));
+
vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_TR], VCPU_SREG_TR);
vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_ES], VCPU_SREG_ES);
vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_DS], VCPU_SREG_DS);
@@ -3226,6 +3250,17 @@ void ept_save_pdptrs(struct kvm_vcpu *vcpu)
#define CR3_EXITING_BITS (CPU_BASED_CR3_LOAD_EXITING | \
CPU_BASED_CR3_STORE_EXITING)
+static bool vmx_is_valid_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
+{
+ if (is_guest_mode(vcpu))
+ return nested_guest_cr0_valid(vcpu, cr0);
+
+ if (to_vmx(vcpu)->nested.vmxon)
+ return nested_host_cr0_valid(vcpu, cr0);
+
+ return true;
+}
+
void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -3235,7 +3270,7 @@ void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
old_cr0_pg = kvm_read_cr0_bits(vcpu, X86_CR0_PG);
hw_cr0 = (cr0 & ~KVM_VM_CR0_ALWAYS_OFF);
- if (is_unrestricted_guest(vcpu))
+ if (enable_unrestricted_guest)
hw_cr0 |= KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST;
else {
hw_cr0 |= KVM_VM_CR0_ALWAYS_ON;
@@ -3263,7 +3298,7 @@ void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
}
#endif
- if (enable_ept && !is_unrestricted_guest(vcpu)) {
+ if (enable_ept && !enable_unrestricted_guest) {
/*
* Ensure KVM has an up-to-date snapshot of the guest's CR3. If
* the below code _enables_ CR3 exiting, vmx_cache_reg() will
@@ -3394,7 +3429,7 @@ void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
* this bit, even if host CR4.MCE == 0.
*/
hw_cr4 = (cr4_read_shadow() & X86_CR4_MCE) | (cr4 & ~X86_CR4_MCE);
- if (is_unrestricted_guest(vcpu))
+ if (enable_unrestricted_guest)
hw_cr4 |= KVM_VM_CR4_ALWAYS_ON_UNRESTRICTED_GUEST;
else if (vmx->rmode.vm86_active)
hw_cr4 |= KVM_RMODE_VM_CR4_ALWAYS_ON;
@@ -3414,7 +3449,7 @@ void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
vcpu->arch.cr4 = cr4;
kvm_register_mark_available(vcpu, VCPU_EXREG_CR4);
- if (!is_unrestricted_guest(vcpu)) {
+ if (!enable_unrestricted_guest) {
if (enable_ept) {
if (!is_paging(vcpu)) {
hw_cr4 &= ~X86_CR4_PAE;
@@ -4651,7 +4686,8 @@ static int vmx_alloc_ipiv_pid_table(struct kvm *kvm)
if (kvm_vmx->pid_table)
return 0;
- pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, vmx_get_pid_table_order(kvm));
+ pages = alloc_pages(GFP_KERNEL_ACCOUNT | __GFP_ZERO,
+ vmx_get_pid_table_order(kvm));
if (!pages)
return -ENOMEM;
@@ -5364,18 +5400,11 @@ static int handle_set_cr0(struct kvm_vcpu *vcpu, unsigned long val)
val = (val & ~vmcs12->cr0_guest_host_mask) |
(vmcs12->guest_cr0 & vmcs12->cr0_guest_host_mask);
- if (!nested_guest_cr0_valid(vcpu, val))
- return 1;
-
if (kvm_set_cr0(vcpu, val))
return 1;
vmcs_writel(CR0_READ_SHADOW, orig_val);
return 0;
} else {
- if (to_vmx(vcpu)->nested.vmxon &&
- !nested_host_cr0_valid(vcpu, val))
- return 1;
-
return kvm_set_cr0(vcpu, val);
}
}
@@ -8203,6 +8232,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
.set_segment = vmx_set_segment,
.get_cpl = vmx_get_cpl,
.get_cs_db_l_bits = vmx_get_cs_db_l_bits,
+ .is_valid_cr0 = vmx_is_valid_cr0,
.set_cr0 = vmx_set_cr0,
.is_valid_cr4 = vmx_is_valid_cr4,
.set_cr4 = vmx_set_cr4,
diff --git a/arch/x86/kvm/vmx/vmx_ops.h b/arch/x86/kvm/vmx/vmx_ops.h
index ce47dc265f89..33af7b4c6eb4 100644
--- a/arch/x86/kvm/vmx/vmx_ops.h
+++ b/arch/x86/kvm/vmx/vmx_ops.h
@@ -10,7 +10,7 @@
#include "vmcs.h"
#include "../x86.h"
-void vmread_error(unsigned long field, bool fault);
+void vmread_error(unsigned long field);
void vmwrite_error(unsigned long field, unsigned long value);
void vmclear_error(struct vmcs *vmcs, u64 phys_addr);
void vmptrld_error(struct vmcs *vmcs, u64 phys_addr);
@@ -31,6 +31,13 @@ void invept_error(unsigned long ext, u64 eptp, gpa_t gpa);
* void vmread_error_trampoline(unsigned long field, bool fault);
*/
extern unsigned long vmread_error_trampoline;
+
+/*
+ * The second VMREAD error trampoline, called from the assembly trampoline,
+ * exists primarily to enable instrumentation for the VM-Fail path.
+ */
+void vmread_error_trampoline2(unsigned long field, bool fault);
+
#endif
static __always_inline void vmcs_check16(unsigned long field)
@@ -101,8 +108,7 @@ static __always_inline unsigned long __vmcs_readl(unsigned long field)
do_fail:
instrumentation_begin();
- WARN_ONCE(1, KBUILD_MODNAME ": vmread failed: field=%lx\n", field);
- pr_warn_ratelimited(KBUILD_MODNAME ": vmread failed: field=%lx\n", field);
+ vmread_error(field);
instrumentation_end();
return 0;