xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

KVM: Handle virtualization instruction #UD faults during reboot

Browse Source 
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>
This commit is contained in:
Avi Kivity
2008-05-13 13:23:38 +03:00
parent 1b7fcd3263
commit 4ecac3fd6d
4 changed files with 64 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
arch/x86/kvm/svm.c
View File

@@ -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