On 10/15/2009 11:41 PM, or...@il.ibm.com wrote:
+
+struct __attribute__ ((__packed__)) shadow_vmcs {
Since this is in guest memory, we need it packed so the binary format is
preserved across migration. Please add a comment so it isn't changed
(at least without changing the revision_id).
vmclear state should be here, that will help multiguest support.
struct nested_vmx {
/* Has the level1 guest done vmxon? */
bool vmxon;
-
+ /* What is the location of the vmcs l1 keeps for l2? (in level1 gpa) */
+ u64 vmptr;
Need to expose it for live migration.
/*
* Level 2 state : includes vmcs,registers and
* a copy of vmcs12 for vmread/vmwrite
*/
struct level_state *l2_state;
+ /* Level 1 state for switching to level 2 and back */
+ struct level_state *l1_state;
This creates a ton of duplication.
Some of the data is completely unnecessary, for example we can
recalculate cr0 from HOST_CR0 and GUEST_CR0.
+
+static int vmptrld(struct kvm_vcpu *vcpu,
+ u64 phys_addr)
+{
+ u8 error;
+
+ asm volatile (__ex(ASM_VMX_VMPTRLD_RAX) "; setna %0"
+ : "=g"(error) : "a"(&phys_addr), "m"(phys_addr)
+ : "cc");
+ if (error) {
+ printk(KERN_ERR "kvm: %s vmptrld %llx failed\n",
+ __func__, phys_addr);
+ return 1;
+ }
+
+ return 0;
+}
+
/*
* Switches to specified vcpu, until a matching vcpu_put(), but assumes
* vcpu mutex is already taken.
@@ -736,15 +923,8 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
}
if (per_cpu(current_vmcs, cpu) != vmx->vmcs) {
- u8 error;
-
per_cpu(current_vmcs, cpu) = vmx->vmcs;
- asm volatile (__ex(ASM_VMX_VMPTRLD_RAX) "; setna %0"
- : "=g"(error) : "a"(&phys_addr), "m"(phys_addr)
- : "cc");
- if (error)
- printk(KERN_ERR "kvm: vmptrld %p/%llx fail\n",
- vmx->vmcs, phys_addr);
+ vmptrld(vcpu, phys_addr);
}
This part of the patch is no longer needed.
+ if (cpu_has_vmx_msr_bitmap())
+ vmx->nested.l2_state->msr_bitmap = vmcs_read64(MSR_BITMAP);
+ else
+ vmx->nested.l2_state->msr_bitmap = 0;
+
+ vmx->nested.l2_state->io_bitmap_a = vmcs_read64(IO_BITMAP_A);
+ vmx->nested.l2_state->io_bitmap_b = vmcs_read64(IO_BITMAP_B);
+
This no longer works, since we don't load the guest vmcs.
+int kvm_read_guest_virt(gva_t addr, void *val, unsigned int bytes,
+ struct kvm_vcpu *vcpu);
Isn't this in a header somewhere?
+
+int read_guest_vmcs_gpa(struct kvm_vcpu *vcpu, u64 *gentry)
+{
+
+ int r = 0;
+
+ r = kvm_read_guest_virt(vcpu->arch.regs[VCPU_REGS_RAX], gentry,
+ sizeof(u64), vcpu);
+ if (r) {
+ printk(KERN_ERR "%s cannot read guest vmcs addr %lx : %d\n",
+ __func__, vcpu->arch.regs[VCPU_REGS_RAX], r);
+ return r;
+ }
+
+ if (!IS_ALIGNED(*gentry, PAGE_SIZE)) {
+ printk(KERN_DEBUG "%s addr %llx not aligned\n",
+ __func__, *gentry);
+ return 1;
+ }
+
+ return 0;
+}
+
Should go through the emulator to evaluate arguments.
+static int handle_vmptrld(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+ struct page *vmcs_page;
+ u64 guest_vmcs_addr;
+
+ if (!nested_vmx_check_permission(vcpu))
+ return 1;
+
+ if (read_guest_vmcs_gpa(vcpu,&guest_vmcs_addr))
+ return 1;
+
+ if (create_l1_state(vcpu)) {
+ printk(KERN_ERR "%s create_l1_state failed\n", __func__);
+ return 1;
+ }
+
+ if (create_l2_state(vcpu)) {
+ printk(KERN_ERR "%s create_l2_state failed\n", __func__);
+ return 1;
+ }
return errors here, so we see the problem.
+
+static int handle_vmptrst(struct kvm_vcpu *vcpu)
+{
+ int r = 0;
+
+ if (!nested_vmx_check_permission(vcpu))
+ return 1;
+
+ r = kvm_write_guest_virt(vcpu->arch.regs[VCPU_REGS_RAX],
+ (void *)&to_vmx(vcpu)->nested.vmptr,
+ sizeof(u64), vcpu);
Emulator again.
+void save_vmcs(struct shadow_vmcs *dst)
+{
+ dst->io_bitmap_a = vmcs_read64(IO_BITMAP_A);
+ dst->io_bitmap_b = vmcs_read64(IO_BITMAP_B);
These (and many others) can never change due to a nested guest running,
so no need to save them.
+ dst->virtual_apic_page_addr = vmcs_read64(VIRTUAL_APIC_PAGE_ADDR);
In general, you need to translate host physical addresses to guest
physical addresses.
+ dst->apic_access_addr = vmcs_read64(APIC_ACCESS_ADDR);
+ if (enable_ept)
+ dst->ept_pointer = vmcs_read64(EPT_POINTER);
+
Not all hosts support these features.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
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