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authorJim Mattson <jmattson@google.com>2018-07-10 11:27:20 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2018-08-06 17:58:30 +0200
commit8fcc4b5923af5de58b80b53a069453b135693304 (patch)
tree303ea1272f24cda3a01ad79d4f90ec82bcc7a002 /Documentation/virtual
parent7f7f1ba33cf2c21d001821313088c231db42ff40 (diff)
downloadlinux-8fcc4b5923af5de58b80b53a069453b135693304.tar.bz2
kvm: nVMX: Introduce KVM_CAP_NESTED_STATE
For nested virtualization L0 KVM is managing a bit of state for L2 guests, this state can not be captured through the currently available IOCTLs. In fact the state captured through all of these IOCTLs is usually a mix of L1 and L2 state. It is also dependent on whether the L2 guest was running at the moment when the process was interrupted to save its state. With this capability, there are two new vcpu ioctls: KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE. These can be used for saving and restoring a VM that is in VMX operation. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: x86@kernel.org Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Jim Mattson <jmattson@google.com> [karahmed@ - rename structs and functions and make them ready for AMD and address previous comments. - handle nested.smm state. - rebase & a bit of refactoring. - Merge 7/8 and 8/8 into one patch. ] Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation/virtual')
-rw-r--r--Documentation/virtual/kvm/api.txt56
1 files changed, 56 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index cb8db4f9d097..7b83b176c662 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -3561,6 +3561,62 @@ Returns: 0 on success,
-ENOENT on deassign if the conn_id isn't registered
-EEXIST on assign if the conn_id is already registered
+4.114 KVM_GET_NESTED_STATE
+
+Capability: KVM_CAP_NESTED_STATE
+Architectures: x86
+Type: vcpu ioctl
+Parameters: struct kvm_nested_state (in/out)
+Returns: 0 on success, -1 on error
+Errors:
+ E2BIG: the total state size (including the fixed-size part of struct
+ kvm_nested_state) exceeds the value of 'size' specified by
+ the user; the size required will be written into size.
+
+struct kvm_nested_state {
+ __u16 flags;
+ __u16 format;
+ __u32 size;
+ union {
+ struct kvm_vmx_nested_state vmx;
+ struct kvm_svm_nested_state svm;
+ __u8 pad[120];
+ };
+ __u8 data[0];
+};
+
+#define KVM_STATE_NESTED_GUEST_MODE 0x00000001
+#define KVM_STATE_NESTED_RUN_PENDING 0x00000002
+
+#define KVM_STATE_NESTED_SMM_GUEST_MODE 0x00000001
+#define KVM_STATE_NESTED_SMM_VMXON 0x00000002
+
+struct kvm_vmx_nested_state {
+ __u64 vmxon_pa;
+ __u64 vmcs_pa;
+
+ struct {
+ __u16 flags;
+ } smm;
+};
+
+This ioctl copies the vcpu's nested virtualization state from the kernel to
+userspace.
+
+The maximum size of the state, including the fixed-size part of struct
+kvm_nested_state, can be retrieved by passing KVM_CAP_NESTED_STATE to
+the KVM_CHECK_EXTENSION ioctl().
+
+4.115 KVM_SET_NESTED_STATE
+
+Capability: KVM_CAP_NESTED_STATE
+Architectures: x86
+Type: vcpu ioctl
+Parameters: struct kvm_nested_state (in)
+Returns: 0 on success, -1 on error
+
+This copies the vcpu's kvm_nested_state struct from userspace to the kernel. For
+the definition of struct kvm_nested_state, see KVM_GET_NESTED_STATE.
5. The kvm_run structure
------------------------