diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 992ab7115871..9390a31c06f4 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -27,6 +27,8 @@ #include +#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 fff8e23433d6..b80b4d141637 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -30,6 +30,8 @@ #include #include +#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 diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h index c2d066e185f4..0df9d5fa281a 100644 --- a/include/asm-x86/kvm_host.h +++ b/include/asm-x86/kvm_host.h @@ -692,4 +692,28 @@ enum { trace_mark(kvm_trace_##name, "%u %p %u %u %u %u %u %u", KVM_TRC_##evt, \ vcpu, 0, 0, 0, 0, 0, 0) +#ifdef CONFIG_64BIT +#define KVM_EX_ENTRY ".quad" +#else +#define KVM_EX_ENTRY ".long" +#endif + +/* + * Hardware virtualization extension instructions may fault if a + * reboot turns off virtualization while processes are running. + * Trap the fault and ignore the instruction if that happens. + */ +asmlinkage void kvm_handle_fault_on_reboot(void); + +#define __kvm_handle_fault_on_reboot(insn) \ + "666: " insn "\n\t" \ + ".pushsection .text.fixup, \"ax\" \n" \ + "667: \n\t" \ + "push $666b \n\t" \ + "jmp kvm_handle_fault_on_reboot \n\t" \ + ".popsection \n\t" \ + ".pushsection __ex_table, \"a\" \n\t" \ + KVM_EX_ENTRY " 666b, 667b \n\t" \ + ".popsection" + #endif diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index f9dd20606c40..e4bf88a9ee4e 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -65,6 +65,8 @@ struct dentry *kvm_debugfs_dir; static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl, unsigned long arg); +bool kvm_rebooting; + static inline int valid_vcpu(int n) { return likely(n >= 0 && n < KVM_MAX_VCPUS); @@ -1301,6 +1303,18 @@ static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val, return NOTIFY_OK; } + +asmlinkage void kvm_handle_fault_on_reboot(void) +{ + if (kvm_rebooting) + /* spin while reset goes on */ + while (true) + ; + /* Fault while not rebooting. We want the trace. */ + BUG(); +} +EXPORT_SYMBOL_GPL(kvm_handle_fault_on_reboot); + static int kvm_reboot(struct notifier_block *notifier, unsigned long val, void *v) { @@ -1310,6 +1324,7 @@ static int kvm_reboot(struct notifier_block *notifier, unsigned long val, * in vmx root mode. */ printk(KERN_INFO "kvm: exiting hardware virtualization\n"); + kvm_rebooting = true; on_each_cpu(hardware_disable, NULL, 1); } return NOTIFY_OK;