mirror of https://gitee.com/openkylin/linux.git
KVM: Add documentation for Xen hypercall and shared_info updates
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
This commit is contained in:
David Woodhouse
parent
8d4e7e8083
commit
e1f68169a4
|
|
@ -960,6 +960,14 @@ memory.
|
|||
__u8 pad2[30];
|
||||
};
|
||||
|
||||
If the KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL flag is returned from the
|
||||
KVM_CAP_XEN_HVM check, it may be set in the flags field of this ioctl.
|
||||
This requests KVM to generate the contents of the hypercall page
|
||||
automatically; hypercalls will be intercepted and passed to userspace
|
||||
through KVM_EXIT_XEN. In this case, all of the blob size and address
|
||||
fields must be zero.
|
||||
|
||||
No other flags are currently valid in the struct kvm_xen_hvm_config.
|
||||
|
||||
4.29 KVM_GET_CLOCK
|
||||
------------------
|
||||
|
|
@ -4831,6 +4839,101 @@ into user space.
|
|||
If a vCPU is in running state while this ioctl is invoked, the vCPU may
|
||||
experience inconsistent filtering behavior on MSR accesses.
|
||||
|
||||
4.127 KVM_XEN_HVM_SET_ATTR
|
||||
--------------------------
|
||||
|
||||
:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
|
||||
:Architectures: x86
|
||||
:Type: vm ioctl
|
||||
:Parameters: struct kvm_xen_hvm_attr
|
||||
:Returns: 0 on success, < 0 on error
|
||||
|
||||
::
|
||||
|
||||
struct kvm_xen_hvm_attr {
|
||||
__u16 type;
|
||||
__u16 pad[3];
|
||||
union {
|
||||
__u8 long_mode;
|
||||
__u8 vector;
|
||||
struct {
|
||||
__u64 gfn;
|
||||
} shared_info;
|
||||
__u64 pad[4];
|
||||
} u;
|
||||
};
|
||||
|
||||
type values:
|
||||
|
||||
KVM_XEN_ATTR_TYPE_LONG_MODE
|
||||
Sets the ABI mode of the VM to 32-bit or 64-bit (long mode). This
|
||||
determines the layout of the shared info pages exposed to the VM.
|
||||
|
||||
KVM_XEN_ATTR_TYPE_SHARED_INFO
|
||||
Sets the guest physical frame number at which the Xen "shared info"
|
||||
page resides. Note that although Xen places vcpu_info for the first
|
||||
32 vCPUs in the shared_info page, KVM does not automatically do so
|
||||
and instead requires that KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO be used
|
||||
explicitly even when the vcpu_info for a given vCPU resides at the
|
||||
"default" location in the shared_info page. This is because KVM is
|
||||
not aware of the Xen CPU id which is used as the index into the
|
||||
vcpu_info[] array, so cannot know the correct default location.
|
||||
|
||||
KVM_XEN_ATTR_TYPE_UPCALL_VECTOR
|
||||
Sets the exception vector used to deliver Xen event channel upcalls.
|
||||
|
||||
4.128 KVM_XEN_HVM_GET_ATTR
|
||||
--------------------------
|
||||
|
||||
:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
|
||||
:Architectures: x86
|
||||
:Type: vm ioctl
|
||||
:Parameters: struct kvm_xen_hvm_attr
|
||||
:Returns: 0 on success, < 0 on error
|
||||
|
||||
Allows Xen VM attributes to be read. For the structure and types,
|
||||
see KVM_XEN_HVM_SET_ATTR above.
|
||||
|
||||
4.129 KVM_XEN_VCPU_SET_ATTR
|
||||
---------------------------
|
||||
|
||||
:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
|
||||
:Architectures: x86
|
||||
:Type: vcpu ioctl
|
||||
:Parameters: struct kvm_xen_vcpu_attr
|
||||
:Returns: 0 on success, < 0 on error
|
||||
|
||||
::
|
||||
|
||||
struct kvm_xen_vcpu_attr {
|
||||
__u16 type;
|
||||
__u16 pad[3];
|
||||
union {
|
||||
__u64 gpa;
|
||||
__u64 pad[4];
|
||||
} u;
|
||||
};
|
||||
|
||||
type values:
|
||||
|
||||
KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO
|
||||
Sets the guest physical address of the vcpu_info for a given vCPU.
|
||||
|
||||
KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO
|
||||
Sets the guest physical address of an additional pvclock structure
|
||||
for a given vCPU. This is typically used for guest vsyscall support.
|
||||
|
||||
4.130 KVM_XEN_VCPU_GET_ATTR
|
||||
--------------------------
|
||||
|
||||
:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
|
||||
:Architectures: x86
|
||||
:Type: vcpu ioctl
|
||||
:Parameters: struct kvm_xen_vcpu_attr
|
||||
:Returns: 0 on success, < 0 on error
|
||||
|
||||
Allows Xen vCPU attributes to be read. For the structure and types,
|
||||
see KVM_XEN_VCPU_SET_ATTR above.
|
||||
|
||||
5. The kvm_run structure
|
||||
========================
|
||||
|
|
@ -4998,13 +5101,18 @@ to the byte array.
|
|||
|
||||
.. note::
|
||||
|
||||
For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR,
|
||||
For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR, KVM_EXIT_XEN,
|
||||
KVM_EXIT_EPR, KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR the corresponding
|
||||
operations are complete (and guest state is consistent) only after userspace
|
||||
has re-entered the kernel with KVM_RUN. The kernel side will first finish
|
||||
incomplete operations and then check for pending signals. Userspace
|
||||
can re-enter the guest with an unmasked signal pending to complete
|
||||
pending operations.
|
||||
incomplete operations and then check for pending signals.
|
||||
|
||||
The pending state of the operation is not preserved in state which is
|
||||
visible to userspace, thus userspace should ensure that the operation is
|
||||
completed before performing a live migration. Userspace can re-enter the
|
||||
guest with an unmasked signal pending or with the immediate_exit field set
|
||||
to complete pending operations without allowing any further instructions
|
||||
to be executed.
|
||||
|
||||
::
|
||||
|
||||
|
|
@ -5329,6 +5437,34 @@ wants to write. Once finished processing the event, user space must continue
|
|||
vCPU execution. If the MSR write was unsuccessful, user space also sets the
|
||||
"error" field to "1".
|
||||
|
||||
::
|
||||
|
||||
|
||||
struct kvm_xen_exit {
|
||||
#define KVM_EXIT_XEN_HCALL 1
|
||||
__u32 type;
|
||||
union {
|
||||
struct {
|
||||
__u32 longmode;
|
||||
__u32 cpl;
|
||||
__u64 input;
|
||||
__u64 result;
|
||||
__u64 params[6];
|
||||
} hcall;
|
||||
} u;
|
||||
};
|
||||
/* KVM_EXIT_XEN */
|
||||
struct kvm_hyperv_exit xen;
|
||||
|
||||
Indicates that the VCPU exits into userspace to process some tasks
|
||||
related to Xen emulation.
|
||||
|
||||
Valid values for 'type' are:
|
||||
|
||||
- KVM_EXIT_XEN_HCALL -- synchronously notify user-space about Xen hypercall.
|
||||
Userspace is expected to place the hypercall result into the appropriate
|
||||
field before invoking KVM_RUN again.
|
||||
|
||||
::
|
||||
|
||||
/* Fix the size of the union. */
|
||||
|
|
@ -6454,7 +6590,6 @@ guest according to the bits in the KVM_CPUID_FEATURES CPUID leaf
|
|||
(0x40000001). Otherwise, a guest may use the paravirtual features
|
||||
regardless of what has actually been exposed through the CPUID leaf.
|
||||
|
||||
|
||||
8.29 KVM_CAP_DIRTY_LOG_RING
|
||||
---------------------------
|
||||
|
||||
|
|
@ -6541,3 +6676,29 @@ KVM_GET_DIRTY_LOG and KVM_CLEAR_DIRTY_LOG. After enabling
|
|||
KVM_CAP_DIRTY_LOG_RING with an acceptable dirty ring size, the virtual
|
||||
machine will switch to ring-buffer dirty page tracking and further
|
||||
KVM_GET_DIRTY_LOG or KVM_CLEAR_DIRTY_LOG ioctls will fail.
|
||||
|
||||
8.30 KVM_CAP_XEN_HVM
|
||||
--------------------
|
||||
|
||||
:Architectures: x86
|
||||
|
||||
This capability indicates the features that Xen supports for hosting Xen
|
||||
PVHVM guests. Valid flags are::
|
||||
|
||||
#define KVM_XEN_HVM_CONFIG_HYPERCALL_MSR (1 << 0)
|
||||
#define KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL (1 << 1)
|
||||
#define KVM_XEN_HVM_CONFIG_SHARED_INFO (1 << 2)
|
||||
|
||||
The KVM_XEN_HVM_CONFIG_HYPERCALL_MSR flag indicates that the KVM_XEN_HVM_CONFIG
|
||||
ioctl is available, for the guest to set its hypercall page.
|
||||
|
||||
If KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL is also set, the same flag may also be
|
||||
provided in the flags to KVM_XEN_HVM_CONFIG, without providing hypercall page
|
||||
contents, to request that KVM generate hypercall page content automatically
|
||||
and also enable interception of guest hypercalls with KVM_EXIT_XEN.
|
||||
|
||||
The KVM_XEN_HVM_CONFIG_SHARED_INFO flag indicates the availability of the
|
||||
KVM_XEN_HVM_SET_ATTR, KVM_XEN_HVM_GET_ATTR, KVM_XEN_VCPU_SET_ATTR and
|
||||
KVM_XEN_VCPU_GET_ATTR ioctls, as well as the delivery of exception vectors
|
||||
for event channel upcalls when the evtchn_upcall_pending field of a vcpu's
|
||||
vcpu_info is set.
|
||||
|
|
|
|||
Loading…
Reference in New Issue