On 28/10/2016 17:29, Jim Mattson wrote:
> After a successful VM-entry with the "VMCS shadowing" VM-execution
> control set, the shadow VMCS referenced by the VMCS link pointer field
> in the current VMCS becomes active on the logical processor.
>
> A VMCS that is made active on more than one logical processor may become
> corrupted. Therefore, before an active VMCS can be migrated to another
> logical processor, the first logical processor must execute a VMCLEAR
> for the active VMCS. VMCLEAR both ensures that all VMCS data are written
> to memory and makes the VMCS inactive.
>
> Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
> Reviewed-By: David Matlack <dmatlack@xxxxxxxxxx>
The patch looks good but---sorry for the possibly stupid
question---where was v1?
Paolo
> ---
> arch/x86/kvm/vmx.c | 22 +++++++++++++++-------
> 1 file changed, 15 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index cf0b7be..046b03f 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -187,6 +187,7 @@ struct vmcs {
> */
> struct loaded_vmcs {
> struct vmcs *vmcs;
> + struct vmcs *shadow_vmcs;
> int cpu;
> int launched;
> struct list_head loaded_vmcss_on_cpu_link;
> @@ -411,7 +412,6 @@ struct nested_vmx {
> * memory during VMXOFF, VMCLEAR, VMPTRLD.
> */
> struct vmcs12 *cached_vmcs12;
> - struct vmcs *current_shadow_vmcs;
> /*
> * Indicates if the shadow vmcs must be updated with the
> * data hold by vmcs12
> @@ -1419,6 +1419,8 @@ static void vmcs_clear(struct vmcs *vmcs)
> static inline void loaded_vmcs_init(struct loaded_vmcs *loaded_vmcs)
> {
> vmcs_clear(loaded_vmcs->vmcs);
> + if (loaded_vmcs->shadow_vmcs && loaded_vmcs->launched)
> + vmcs_clear(loaded_vmcs->shadow_vmcs);
> loaded_vmcs->cpu = -1;
> loaded_vmcs->launched = 0;
> }
> @@ -3562,6 +3564,7 @@ static void free_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
> loaded_vmcs_clear(loaded_vmcs);
> free_vmcs(loaded_vmcs->vmcs);
> loaded_vmcs->vmcs = NULL;
> + WARN_ON(loaded_vmcs->shadow_vmcs != NULL);
> }
>
> static void free_kvm_area(void)
> @@ -6696,6 +6699,7 @@ static struct loaded_vmcs *nested_get_current_vmcs02(struct vcpu_vmx *vmx)
> if (!item)
> return NULL;
> item->vmcs02.vmcs = alloc_vmcs();
> + item->vmcs02.shadow_vmcs = NULL;
> if (!item->vmcs02.vmcs) {
> kfree(item);
> return NULL;
> @@ -7072,7 +7076,7 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
> shadow_vmcs->revision_id |= (1u << 31);
> /* init shadow vmcs */
> vmcs_clear(shadow_vmcs);
> - vmx->nested.current_shadow_vmcs = shadow_vmcs;
> + vmx->vmcs01.shadow_vmcs = shadow_vmcs;
> }
>
> INIT_LIST_HEAD(&(vmx->nested.vmcs02_pool));
> @@ -7174,8 +7178,11 @@ static void free_nested(struct vcpu_vmx *vmx)
> free_page((unsigned long)vmx->nested.msr_bitmap);
> vmx->nested.msr_bitmap = NULL;
> }
> - if (enable_shadow_vmcs)
> - free_vmcs(vmx->nested.current_shadow_vmcs);
> + if (enable_shadow_vmcs) {
> + vmcs_clear(vmx->vmcs01.shadow_vmcs);
> + free_vmcs(vmx->vmcs01.shadow_vmcs);
> + vmx->vmcs01.shadow_vmcs = NULL;
> + }
> kfree(vmx->nested.cached_vmcs12);
> /* Unpin physical memory we referred to in current vmcs02 */
> if (vmx->nested.apic_access_page) {
> @@ -7352,7 +7359,7 @@ static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx)
> int i;
> unsigned long field;
> u64 field_value;
> - struct vmcs *shadow_vmcs = vmx->nested.current_shadow_vmcs;
> + struct vmcs *shadow_vmcs = vmx->vmcs01.shadow_vmcs;
> const unsigned long *fields = shadow_read_write_fields;
> const int num_fields = max_shadow_read_write_fields;
>
> @@ -7401,7 +7408,7 @@ static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx)
> int i, q;
> unsigned long field;
> u64 field_value = 0;
> - struct vmcs *shadow_vmcs = vmx->nested.current_shadow_vmcs;
> + struct vmcs *shadow_vmcs = vmx->vmcs01.shadow_vmcs;
>
> vmcs_load(shadow_vmcs);
>
> @@ -7591,7 +7598,7 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu)
> vmcs_set_bits(SECONDARY_VM_EXEC_CONTROL,
> SECONDARY_EXEC_SHADOW_VMCS);
> vmcs_write64(VMCS_LINK_POINTER,
> - __pa(vmx->nested.current_shadow_vmcs));
> + __pa(vmx->vmcs01.shadow_vmcs));
> vmx->nested.sync_shadow_vmcs = true;
> }
> }
> @@ -9156,6 +9163,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
>
> vmx->loaded_vmcs = &vmx->vmcs01;
> vmx->loaded_vmcs->vmcs = alloc_vmcs();
> + vmx->loaded_vmcs->shadow_vmcs = NULL;
> if (!vmx->loaded_vmcs->vmcs)
> goto free_msrs;
> if (!vmm_exclusive)
>
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