diff options
| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2019-07-19 13:41:08 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-09-25 15:30:09 +0200 |
| commit | 6e2020977e3e692a8bb31258c1f8251521f4fdb7 (patch) | |
| tree | 19b899e36297b4aa35daeb68417e7a49a3346cc3 /arch | |
| parent | 52a9fcbc73a30375cad8d9e7b519e1ad97b0880a (diff) | |
| download | linux-6e2020977e3e692a8bb31258c1f8251521f4fdb7.tar.bz2 | |
KVM: VMX: Add error handling to VMREAD helper
Now that VMREAD flows require a taken branch, courtesy of commit
3901336ed9887 ("x86/kvm: Don't call kvm_spurious_fault() from .fixup")
bite the bullet and add full error handling to VMREAD, i.e. replace the
JMP added by __ex()/____kvm_handle_fault_on_reboot() with a hinted Jcc.
To minimize the code footprint, add a helper function, vmread_error(),
to handle both faults and failures so that the inline flow has a single
CALL.
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/vmx/ops.h | 21 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 8 |
2 files changed, 25 insertions, 4 deletions
diff --git a/arch/x86/kvm/vmx/ops.h b/arch/x86/kvm/vmx/ops.h index 79e25d49d4d9..45eaedee2ac0 100644 --- a/arch/x86/kvm/vmx/ops.h +++ b/arch/x86/kvm/vmx/ops.h @@ -11,9 +11,8 @@ #include "vmcs.h" #define __ex(x) __kvm_handle_fault_on_reboot(x) -#define __ex_clear(x, reg) \ - ____kvm_handle_fault_on_reboot(x, "xor " reg ", " reg) +asmlinkage void vmread_error(unsigned long field, bool fault); 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); @@ -68,8 +67,22 @@ static __always_inline unsigned long __vmcs_readl(unsigned long field) { unsigned long value; - asm volatile (__ex_clear("vmread %1, %0", "%k0") - : "=r"(value) : "r"(field)); + asm volatile("1: vmread %2, %1\n\t" + ".byte 0x3e\n\t" /* branch taken hint */ + "ja 3f\n\t" + "mov %2, %%" _ASM_ARG1 "\n\t" + "xor %%" _ASM_ARG2 ", %%" _ASM_ARG2 "\n\t" + "2: call vmread_error\n\t" + "xor %k1, %k1\n\t" + "3:\n\t" + + ".pushsection .fixup, \"ax\"\n\t" + "4: mov %2, %%" _ASM_ARG1 "\n\t" + "mov $1, %%" _ASM_ARG2 "\n\t" + "jmp 2b\n\t" + ".popsection\n\t" + _ASM_EXTABLE(1b, 4b) + : ASM_CALL_CONSTRAINT, "=r"(value) : "r"(field) : "cc"); return value; } diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 52c7614b5ecd..1852706e6acc 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -349,6 +349,14 @@ do { \ pr_warn_ratelimited(fmt); \ } while (0) +asmlinkage void vmread_error(unsigned long field, bool fault) +{ + if (fault) + kvm_spurious_fault(); + else + vmx_insn_failed("kvm: vmread failed: field=%lx\n", field); +} + noinline void vmwrite_error(unsigned long field, unsigned long value) { vmx_insn_failed("kvm: vmwrite failed: field=%lx val=%lx err=%d\n", |