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authorAvi Kivity <avi@qumranet.com>2008-05-13 13:23:38 +0300
committerAvi Kivity <avi@qumranet.com>2008-07-20 12:41:43 +0300
commit4ecac3fd6dc2629ad76a658a486f081c44aef10e (patch)
treea078acb4c626432ac8cf887b911d912f4a316d06 /arch/x86
parent1b7fcd3263e5f12dba43d27b64e1578bec070c28 (diff)
KVM: Handle virtualization instruction #UD faults during reboot
KVM turns off hardware virtualization extensions during reboot, in order to disassociate the memory used by the virtualization extensions from the processor, and in order to have the system in a consistent state. Unfortunately virtual machines may still be running while this goes on, and once virtualization extensions are turned off, any virtulization instruction will #UD on execution. Fix by adding an exception handler to virtualization instructions; if we get an exception during reboot, we simply spin waiting for the reset to complete. If it's a true exception, BUG() so we can have our stack trace. Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/svm.c20
-rw-r--r--arch/x86/kvm/vmx.c25
2 files changed, 25 insertions, 20 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 992ab711587..9390a31c06f 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -27,6 +27,8 @@
#include <asm/desc.h>
+#define __ex(x) __kvm_handle_fault_on_reboot(x)
+
MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");
@@ -129,17 +131,17 @@ static inline void push_irq(struct kvm_vcpu *vcpu, u8 irq)
static inline void clgi(void)
{
- asm volatile (SVM_CLGI);
+ asm volatile (__ex(SVM_CLGI));
}
static inline void stgi(void)
{
- asm volatile (SVM_STGI);
+ asm volatile (__ex(SVM_STGI));
}
static inline void invlpga(unsigned long addr, u32 asid)
{
- asm volatile (SVM_INVLPGA :: "a"(addr), "c"(asid));
+ asm volatile (__ex(SVM_INVLPGA) :: "a"(addr), "c"(asid));
}
static inline unsigned long kvm_read_cr2(void)
@@ -1758,17 +1760,17 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
/* Enter guest mode */
"push %%rax \n\t"
"mov %c[vmcb](%[svm]), %%rax \n\t"
- SVM_VMLOAD "\n\t"
- SVM_VMRUN "\n\t"
- SVM_VMSAVE "\n\t"
+ __ex(SVM_VMLOAD) "\n\t"
+ __ex(SVM_VMRUN) "\n\t"
+ __ex(SVM_VMSAVE) "\n\t"
"pop %%rax \n\t"
#else
/* Enter guest mode */
"push %%eax \n\t"
"mov %c[vmcb](%[svm]), %%eax \n\t"
- SVM_VMLOAD "\n\t"
- SVM_VMRUN "\n\t"
- SVM_VMSAVE "\n\t"
+ __ex(SVM_VMLOAD) "\n\t"
+ __ex(SVM_VMRUN) "\n\t"
+ __ex(SVM_VMSAVE) "\n\t"
"pop %%eax \n\t"
#endif
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index fff8e23433d..b80b4d14163 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -30,6 +30,8 @@
#include <asm/io.h>
#include <asm/desc.h>
+#define __ex(x) __kvm_handle_fault_on_reboot(x)
+
MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");
@@ -278,7 +280,7 @@ static inline void __invvpid(int ext, u16 vpid, gva_t gva)
u64 gva;
} operand = { vpid, 0, gva };
- asm volatile (ASM_VMX_INVVPID
+ asm volatile (__ex(ASM_VMX_INVVPID)
/* CF==1 or ZF==1 --> rc = -1 */
"; ja 1f ; ud2 ; 1:"
: : "a"(&operand), "c"(ext) : "cc", "memory");
@@ -290,7 +292,7 @@ static inline void __invept(int ext, u64 eptp, gpa_t gpa)
u64 eptp, gpa;
} operand = {eptp, gpa};
- asm volatile (ASM_VMX_INVEPT
+ asm volatile (__ex(ASM_VMX_INVEPT)
/* CF==1 or ZF==1 --> rc = -1 */
"; ja 1f ; ud2 ; 1:\n"
: : "a" (&operand), "c" (ext) : "cc", "memory");
@@ -311,7 +313,7 @@ static void vmcs_clear(struct vmcs *vmcs)
u64 phys_addr = __pa(vmcs);
u8 error;
- asm volatile (ASM_VMX_VMCLEAR_RAX "; setna %0"
+ asm volatile (__ex(ASM_VMX_VMCLEAR_RAX) "; setna %0"
: "=g"(error) : "a"(&phys_addr), "m"(phys_addr)
: "cc", "memory");
if (error)
@@ -378,7 +380,7 @@ static unsigned long vmcs_readl(unsigned long field)
{
unsigned long value;
- asm volatile (ASM_VMX_VMREAD_RDX_RAX
+ asm volatile (__ex(ASM_VMX_VMREAD_RDX_RAX)
: "=a"(value) : "d"(field) : "cc");
return value;
}
@@ -413,7 +415,7 @@ static void vmcs_writel(unsigned long field, unsigned long value)
{
u8 error;
- asm volatile (ASM_VMX_VMWRITE_RAX_RDX "; setna %0"
+ asm volatile (__ex(ASM_VMX_VMWRITE_RAX_RDX) "; setna %0"
: "=q"(error) : "a"(value), "d"(field) : "cc");
if (unlikely(error))
vmwrite_error(field, value);
@@ -621,7 +623,7 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
u8 error;
per_cpu(current_vmcs, cpu) = vmx->vmcs;
- asm volatile (ASM_VMX_VMPTRLD_RAX "; setna %0"
+ asm volatile (__ex(ASM_VMX_VMPTRLD_RAX) "; setna %0"
: "=g"(error) : "a"(&phys_addr), "m"(phys_addr)
: "cc");
if (error)
@@ -1030,13 +1032,14 @@ static void hardware_enable(void *garbage)
MSR_IA32_FEATURE_CONTROL_LOCKED |
MSR_IA32_FEATURE_CONTROL_VMXON_ENABLED);
write_cr4(read_cr4() | X86_CR4_VMXE); /* FIXME: not cpu hotplug safe */
- asm volatile (ASM_VMX_VMXON_RAX : : "a"(&phys_addr), "m"(phys_addr)
+ asm volatile (ASM_VMX_VMXON_RAX
+ : : "a"(&phys_addr), "m"(phys_addr)
: "memory", "cc");
}
static void hardware_disable(void *garbage)
{
- asm volatile (ASM_VMX_VMXOFF : : : "cc");
+ asm volatile (__ex(ASM_VMX_VMXOFF) : : : "cc");
write_cr4(read_cr4() & ~X86_CR4_VMXE);
}
@@ -2834,7 +2837,7 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
"push %%edx; push %%ebp;"
"push %%ecx \n\t"
#endif
- ASM_VMX_VMWRITE_RSP_RDX "\n\t"
+ __ex(ASM_VMX_VMWRITE_RSP_RDX) "\n\t"
/* Check if vmlaunch of vmresume is needed */
"cmpl $0, %c[launched](%0) \n\t"
/* Load guest registers. Don't clobber flags. */
@@ -2869,9 +2872,9 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
#endif
/* Enter guest mode */
"jne .Llaunched \n\t"
- ASM_VMX_VMLAUNCH "\n\t"
+ __ex(ASM_VMX_VMLAUNCH) "\n\t"
"jmp .Lkvm_vmx_return \n\t"
- ".Llaunched: " ASM_VMX_VMRESUME "\n\t"
+ ".Llaunched: " __ex(ASM_VMX_VMRESUME) "\n\t"
".Lkvm_vmx_return: "
/* Save guest registers, load host registers, keep flags */
#ifdef CONFIG_X86_64