On 06/13/2010 03:24 PM, Nadav Har'El wrote:
This patch allows a guest to use the VMXON and VMXOFF instructions, and
emulates them accordingly. Basically this amounts to checking some
prerequisites, and then remembering whether the guest has enabled or disabled
VMX operation.
Should probably reorder with next patch.
+/* The nested_vmx structure is part of vcpu_vmx, and holds information we need
+ * for correct emulation of VMX (i.e., nested VMX) on this vcpu. For example,
+ * the current VMCS set by L1, a list of the VMCSs used to run the active
+ * L2 guests on the hardware, and more.
+ */
Please (here and elsewhere) use the standard kernel style for multiline
comments - start with /* on a line by itself.
+/* Emulate the VMXON instruction.
+ * Currently, we just remember that VMX is active, and do not save or even
+ * inspect the argument to VMXON (the so-called "VMXON pointer") because we
+ * do not currently need to store anything in that guest-allocated memory
+ * region. Consequently, VMCLEAR and VMPTRLD also do not verify that the their
+ * argument is different from the VMXON pointer (which the spec says they do).
+ */
+static int handle_vmon(struct kvm_vcpu *vcpu)
+{
+ struct kvm_segment cs;
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+ /* The Intel VMX Instruction Reference lists a bunch of bits that
+ * are prerequisite to running VMXON, most notably CR4.VMXE must be
+ * set to 1. Otherwise, we should fail with #UD. We test these now:
+ */
+ if (!nested) {
+ kvm_queue_exception(vcpu, UD_VECTOR);
+ return 1;
+ }
+
+ if (!(vcpu->arch.cr4& X86_CR4_VMXE) ||
+ !(vcpu->arch.cr0& X86_CR0_PE) ||
+ (vmx_get_rflags(vcpu)& X86_EFLAGS_VM)) {
+ kvm_queue_exception(vcpu, UD_VECTOR);
+ return 1;
+ }
+
+ vmx_get_segment(vcpu,&cs, VCPU_SREG_CS);
+ if (is_long_mode(vcpu)&& !cs.l) {
+ kvm_queue_exception(vcpu, UD_VECTOR);
+ return 1;
+ }
+
+ if (vmx_get_cpl(vcpu)) {
+ kvm_inject_gp(vcpu, 0);
+ return 1;
+ }
+
+ vmx->nested.vmxon = 1;
= true
+
+ skip_emulated_instruction(vcpu);
+ return 1;
+}
Need to block INIT signals in the local apic as well (fine for a
separate patch).
--
error compiling committee.c: too many arguments to function
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