KVM: nVMX: Implement VMCLEAR

This patch implements the VMCLEAR instruction.

Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 8432448..c760000 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -166,6 +166,9 @@ struct __packed vmcs12 {
        u32 revision_id;
        u32 abort;
 
+       u32 launch_state; /* set to 0 by VMCLEAR, to 1 by VMLAUNCH */
+       u32 padding[7]; /* room for future expansion */
+
        u64 io_bitmap_a;
        u64 io_bitmap_b;
        u64 msr_bitmap;
@@ -4814,6 +4817,66 @@ static void nested_vmx_failValid(struct kvm_vcpu *vcpu,
        get_vmcs12(vcpu)->vm_instruction_error = vm_instruction_error;
 }
 
+/* Emulate the VMCLEAR instruction */
+static int handle_vmclear(struct kvm_vcpu *vcpu)
+{
+       struct vcpu_vmx *vmx = to_vmx(vcpu);
+       gva_t gva;
+       gpa_t vmptr;
+       struct vmcs12 *vmcs12;
+       struct page *page;
+       struct x86_exception e;
+
+       if (!nested_vmx_check_permission(vcpu))
+               return 1;
+
+       if (get_vmx_mem_address(vcpu, vmcs_readl(EXIT_QUALIFICATION),
+                       vmcs_read32(VMX_INSTRUCTION_INFO), &gva))
+               return 1;
+
+       if (kvm_read_guest_virt(&vcpu->arch.emulate_ctxt, gva, &vmptr,
+                               sizeof(vmptr), &e)) {
+               kvm_inject_page_fault(vcpu, &e);
+               return 1;
+       }
+
+       if (!IS_ALIGNED(vmptr, PAGE_SIZE)) {
+               nested_vmx_failValid(vcpu, VMXERR_VMCLEAR_INVALID_ADDRESS);
+               skip_emulated_instruction(vcpu);
+               return 1;
+       }
+
+       if (vmptr == vmx->nested.current_vmptr) {
+               kunmap(vmx->nested.current_vmcs12_page);
+               nested_release_page(vmx->nested.current_vmcs12_page);
+               vmx->nested.current_vmptr = -1ull;
+               vmx->nested.current_vmcs12 = NULL;
+       }
+
+       page = nested_get_page(vcpu, vmptr);
+       if (page == NULL) {
+               /*
+                * For accurate processor emulation, VMCLEAR beyond available
+                * physical memory should do nothing at all. However, it is
+                * possible that a nested vmx bug, not a guest hypervisor bug,
+                * resulted in this case, so let's shut down before doing any
+                * more damage:
+                */
+               kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
+               return 1;
+       }
+       vmcs12 = kmap(page);
+       vmcs12->launch_state = 0;
+       kunmap(page);
+       nested_release_page(page);
+
+       nested_free_vmcs02(vmx, vmptr);
+
+       skip_emulated_instruction(vcpu);
+       nested_vmx_succeed(vcpu);
+       return 1;
+}
+
 /*
  * The exit handlers return 1 if the exit was handled fully and guest execution
  * may resume.  Otherwise they set the kvm_run parameter to indicate what needs
@@ -4835,7 +4898,7 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
        [EXIT_REASON_INVD]                    = handle_invd,
        [EXIT_REASON_INVLPG]                  = handle_invlpg,
        [EXIT_REASON_VMCALL]                  = handle_vmcall,
-       [EXIT_REASON_VMCLEAR]                 = handle_vmx_insn,
+       [EXIT_REASON_VMCLEAR]                 = handle_vmclear,
        [EXIT_REASON_VMLAUNCH]                = handle_vmx_insn,
        [EXIT_REASON_VMPTRLD]                 = handle_vmx_insn,
        [EXIT_REASON_VMPTRST]                 = handle_vmx_insn,

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 27d12a3..c1b5a18 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -347,6 +347,7 @@ void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault)
        vcpu->arch.cr2 = fault->address;
        kvm_queue_exception_e(vcpu, PF_VECTOR, fault->error_code);
 }
+EXPORT_SYMBOL_GPL(kvm_inject_page_fault);
 
 void kvm_propagate_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault)
 {