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| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2019-07-19 13:41:07 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-09-25 15:30:02 +0200 |
| commit | 52a9fcbc73a30375cad8d9e7b519e1ad97b0880a (patch) | |
| tree | 812106f6a34356896c0e3cb25c2b76cf60987208 /arch/x86/kvm/vmx/vmx.c | |
| parent | 4b526de50e39b38cd828396267379183c7c21354 (diff) | |
| download | lwn-52a9fcbc73a30375cad8d9e7b519e1ad97b0880a.tar.gz lwn-52a9fcbc73a30375cad8d9e7b519e1ad97b0880a.zip | |
KVM: VMX: Optimize VMX instruction error and fault handling
Rework the VMX instruction helpers using asm-goto to branch directly
to error/fault "handlers" in lieu of using __ex(), i.e. the generic
____kvm_handle_fault_on_reboot(). Branching directly to fault handling
code during fixup avoids the extra JMP that is inserted after every VMX
instruction when using the generic "fault on reboot" (see commit
3901336ed9887, "x86/kvm: Don't call kvm_spurious_fault() from .fixup").
Opportunistically clean up the helpers so that they all have consistent
error handling and messages.
Leave the usage of ____kvm_handle_fault_on_reboot() (via __ex()) in
kvm_cpu_vmxoff() and nested_vmx_check_vmentry_hw() as is. The VMXOFF
case is not a fast path, i.e. the cleanliness of __ex() is worth the
JMP, and the extra JMP in nested_vmx_check_vmentry_hw() is unavoidable.
Note, VMREAD cannot get the asm-goto treatment as output operands aren't
compatible with GCC's asm-goto due to internal compiler restrictions.
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/x86/kvm/vmx/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index a7c9922e3905..52c7614b5ecd 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -343,6 +343,40 @@ static __always_inline void vmx_disable_intercept_for_msr(unsigned long *msr_bit void vmx_vmexit(void); +#define vmx_insn_failed(fmt...) \ +do { \ + WARN_ONCE(1, fmt); \ + pr_warn_ratelimited(fmt); \ +} while (0) + +noinline void vmwrite_error(unsigned long field, unsigned long value) +{ + vmx_insn_failed("kvm: vmwrite failed: field=%lx val=%lx err=%d\n", + field, value, vmcs_read32(VM_INSTRUCTION_ERROR)); +} + +noinline void vmclear_error(struct vmcs *vmcs, u64 phys_addr) +{ + vmx_insn_failed("kvm: vmclear failed: %p/%llx\n", vmcs, phys_addr); +} + +noinline void vmptrld_error(struct vmcs *vmcs, u64 phys_addr) +{ + vmx_insn_failed("kvm: vmptrld failed: %p/%llx\n", vmcs, phys_addr); +} + +noinline void invvpid_error(unsigned long ext, u16 vpid, gva_t gva) +{ + vmx_insn_failed("kvm: invvpid failed: ext=0x%lx vpid=%u gva=0x%lx\n", + ext, vpid, gva); +} + +noinline void invept_error(unsigned long ext, u64 eptp, gpa_t gpa) +{ + vmx_insn_failed("kvm: invept failed: ext=0x%lx eptp=%llx gpa=0x%llx\n", + ext, eptp, gpa); +} + static DEFINE_PER_CPU(struct vmcs *, vmxarea); DEFINE_PER_CPU(struct vmcs *, current_vmcs); /* |