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authorLinus Torvalds <torvalds@linux-foundation.org>2018-10-26 02:57:35 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-26 02:57:35 +0200
commit0d1e8b8d2bcd3150d51754d8d0fdbf44dc88b0d3 (patch)
tree2794cb2347daa76b00160a6ffb68663f4138dcc7 /Documentation/virtual
parentMerge branch 'for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/c... (diff)
parentKVM/nVMX: Do not validate that posted_intr_desc_addr is page aligned (diff)
downloadlinux-0d1e8b8d2bcd3150d51754d8d0fdbf44dc88b0d3.tar.xz
linux-0d1e8b8d2bcd3150d51754d8d0fdbf44dc88b0d3.zip
Merge tag 'kvm-4.20-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Radim Krčmář: "ARM: - Improved guest IPA space support (32 to 52 bits) - RAS event delivery for 32bit - PMU fixes - Guest entry hardening - Various cleanups - Port of dirty_log_test selftest PPC: - Nested HV KVM support for radix guests on POWER9. The performance is much better than with PR KVM. Migration and arbitrary level of nesting is supported. - Disable nested HV-KVM on early POWER9 chips that need a particular hardware bug workaround - One VM per core mode to prevent potential data leaks - PCI pass-through optimization - merge ppc-kvm topic branch and kvm-ppc-fixes to get a better base s390: - Initial version of AP crypto virtualization via vfio-mdev - Improvement for vfio-ap - Set the host program identifier - Optimize page table locking x86: - Enable nested virtualization by default - Implement Hyper-V IPI hypercalls - Improve #PF and #DB handling - Allow guests to use Enlightened VMCS - Add migration selftests for VMCS and Enlightened VMCS - Allow coalesced PIO accesses - Add an option to perform nested VMCS host state consistency check through hardware - Automatic tuning of lapic_timer_advance_ns - Many fixes, minor improvements, and cleanups" * tag 'kvm-4.20-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (204 commits) KVM/nVMX: Do not validate that posted_intr_desc_addr is page aligned Revert "kvm: x86: optimize dr6 restore" KVM: PPC: Optimize clearing TCEs for sparse tables x86/kvm/nVMX: tweak shadow fields selftests/kvm: add missing executables to .gitignore KVM: arm64: Safety check PSTATE when entering guest and handle IL KVM: PPC: Book3S HV: Don't use streamlined entry path on early POWER9 chips arm/arm64: KVM: Enable 32 bits kvm vcpu events support arm/arm64: KVM: Rename function kvm_arch_dev_ioctl_check_extension() KVM: arm64: Fix caching of host MDCR_EL2 value KVM: VMX: enable nested virtualization by default KVM/x86: Use 32bit xor to clear registers in svm.c kvm: x86: Introduce KVM_CAP_EXCEPTION_PAYLOAD kvm: vmx: Defer setting of DR6 until #DB delivery kvm: x86: Defer setting of CR2 until #PF delivery kvm: x86: Add payload operands to kvm_multiple_exception kvm: x86: Add exception payload fields to kvm_vcpu_events kvm: x86: Add has_payload and payload to kvm_queued_exception KVM: Documentation: Fix omission in struct kvm_vcpu_events KVM: selftests: add Enlightened VMCS test ...
Diffstat (limited to 'Documentation/virtual')
-rw-r--r--Documentation/virtual/kvm/api.txt135
1 files changed, 129 insertions, 6 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 647f94128a85..cd209f7730af 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -123,6 +123,37 @@ memory layout to fit in user mode), check KVM_CAP_MIPS_VZ and use the
flag KVM_VM_MIPS_VZ.
+On arm64, the physical address size for a VM (IPA Size limit) is limited
+to 40bits by default. The limit can be configured if the host supports the
+extension KVM_CAP_ARM_VM_IPA_SIZE. When supported, use
+KVM_VM_TYPE_ARM_IPA_SIZE(IPA_Bits) to set the size in the machine type
+identifier, where IPA_Bits is the maximum width of any physical
+address used by the VM. The IPA_Bits is encoded in bits[7-0] of the
+machine type identifier.
+
+e.g, to configure a guest to use 48bit physical address size :
+
+ vm_fd = ioctl(dev_fd, KVM_CREATE_VM, KVM_VM_TYPE_ARM_IPA_SIZE(48));
+
+The requested size (IPA_Bits) must be :
+ 0 - Implies default size, 40bits (for backward compatibility)
+
+ or
+
+ N - Implies N bits, where N is a positive integer such that,
+ 32 <= N <= Host_IPA_Limit
+
+Host_IPA_Limit is the maximum possible value for IPA_Bits on the host and
+is dependent on the CPU capability and the kernel configuration. The limit can
+be retrieved using KVM_CAP_ARM_VM_IPA_SIZE of the KVM_CHECK_EXTENSION
+ioctl() at run-time.
+
+Please note that configuring the IPA size does not affect the capability
+exposed by the guest CPUs in ID_AA64MMFR0_EL1[PARange]. It only affects
+size of the address translated by the stage2 level (guest physical to
+host physical address translations).
+
+
4.3 KVM_GET_MSR_INDEX_LIST, KVM_GET_MSR_FEATURE_INDEX_LIST
Capability: basic, KVM_CAP_GET_MSR_FEATURES for KVM_GET_MSR_FEATURE_INDEX_LIST
@@ -850,7 +881,7 @@ struct kvm_vcpu_events {
__u8 injected;
__u8 nr;
__u8 has_error_code;
- __u8 pad;
+ __u8 pending;
__u32 error_code;
} exception;
struct {
@@ -873,15 +904,23 @@ struct kvm_vcpu_events {
__u8 smm_inside_nmi;
__u8 latched_init;
} smi;
+ __u8 reserved[27];
+ __u8 exception_has_payload;
+ __u64 exception_payload;
};
-Only two fields are defined in the flags field:
+The following bits are defined in the flags field:
-- KVM_VCPUEVENT_VALID_SHADOW may be set in the flags field to signal that
+- KVM_VCPUEVENT_VALID_SHADOW may be set to signal that
interrupt.shadow contains a valid state.
-- KVM_VCPUEVENT_VALID_SMM may be set in the flags field to signal that
- smi contains a valid state.
+- KVM_VCPUEVENT_VALID_SMM may be set to signal that smi contains a
+ valid state.
+
+- KVM_VCPUEVENT_VALID_PAYLOAD may be set to signal that the
+ exception_has_payload, exception_payload, and exception.pending
+ fields contain a valid state. This bit will be set whenever
+ KVM_CAP_EXCEPTION_PAYLOAD is enabled.
ARM/ARM64:
@@ -961,6 +1000,11 @@ shall be written into the VCPU.
KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available.
+If KVM_CAP_EXCEPTION_PAYLOAD is enabled, KVM_VCPUEVENT_VALID_PAYLOAD
+can be set in the flags field to signal that the
+exception_has_payload, exception_payload, and exception.pending fields
+contain a valid state and shall be written into the VCPU.
+
ARM/ARM64:
Set the pending SError exception state for this VCPU. It is not possible to
@@ -1922,6 +1966,7 @@ registers, find a list below:
PPC | KVM_REG_PPC_TIDR | 64
PPC | KVM_REG_PPC_PSSCR | 64
PPC | KVM_REG_PPC_DEC_EXPIRY | 64
+ PPC | KVM_REG_PPC_PTCR | 64
PPC | KVM_REG_PPC_TM_GPR0 | 64
...
PPC | KVM_REG_PPC_TM_GPR31 | 64
@@ -2269,6 +2314,10 @@ The supported flags are:
The emulated MMU supports 1T segments in addition to the
standard 256M ones.
+ - KVM_PPC_NO_HASH
+ This flag indicates that HPT guests are not supported by KVM,
+ thus all guests must use radix MMU mode.
+
The "slb_size" field indicates how many SLB entries are supported
The "sps" array contains 8 entries indicating the supported base
@@ -3676,6 +3725,34 @@ 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.
+4.116 KVM_(UN)REGISTER_COALESCED_MMIO
+
+Capability: KVM_CAP_COALESCED_MMIO (for coalesced mmio)
+ KVM_CAP_COALESCED_PIO (for coalesced pio)
+Architectures: all
+Type: vm ioctl
+Parameters: struct kvm_coalesced_mmio_zone
+Returns: 0 on success, < 0 on error
+
+Coalesced I/O is a performance optimization that defers hardware
+register write emulation so that userspace exits are avoided. It is
+typically used to reduce the overhead of emulating frequently accessed
+hardware registers.
+
+When a hardware register is configured for coalesced I/O, write accesses
+do not exit to userspace and their value is recorded in a ring buffer
+that is shared between kernel and userspace.
+
+Coalesced I/O is used if one or more write accesses to a hardware
+register can be deferred until a read or a write to another hardware
+register on the same device. This last access will cause a vmexit and
+userspace will process accesses from the ring buffer before emulating
+it. That will avoid exiting to userspace on repeated writes.
+
+Coalesced pio is based on coalesced mmio. There is little difference
+between coalesced mmio and pio except that coalesced pio records accesses
+to I/O ports.
+
5. The kvm_run structure
------------------------
@@ -4522,7 +4599,7 @@ hpage module parameter is not set to 1, -EINVAL is returned.
While it is generally possible to create a huge page backed VM without
this capability, the VM will not be able to run.
-7.14 KVM_CAP_MSR_PLATFORM_INFO
+7.15 KVM_CAP_MSR_PLATFORM_INFO
Architectures: x86
Parameters: args[0] whether feature should be enabled or not
@@ -4531,6 +4608,45 @@ With this capability, a guest may read the MSR_PLATFORM_INFO MSR. Otherwise,
a #GP would be raised when the guest tries to access. Currently, this
capability does not enable write permissions of this MSR for the guest.
+7.16 KVM_CAP_PPC_NESTED_HV
+
+Architectures: ppc
+Parameters: none
+Returns: 0 on success, -EINVAL when the implementation doesn't support
+ nested-HV virtualization.
+
+HV-KVM on POWER9 and later systems allows for "nested-HV"
+virtualization, which provides a way for a guest VM to run guests that
+can run using the CPU's supervisor mode (privileged non-hypervisor
+state). Enabling this capability on a VM depends on the CPU having
+the necessary functionality and on the facility being enabled with a
+kvm-hv module parameter.
+
+7.17 KVM_CAP_EXCEPTION_PAYLOAD
+
+Architectures: x86
+Parameters: args[0] whether feature should be enabled or not
+
+With this capability enabled, CR2 will not be modified prior to the
+emulated VM-exit when L1 intercepts a #PF exception that occurs in
+L2. Similarly, for kvm-intel only, DR6 will not be modified prior to
+the emulated VM-exit when L1 intercepts a #DB exception that occurs in
+L2. As a result, when KVM_GET_VCPU_EVENTS reports a pending #PF (or
+#DB) exception for L2, exception.has_payload will be set and the
+faulting address (or the new DR6 bits*) will be reported in the
+exception_payload field. Similarly, when userspace injects a #PF (or
+#DB) into L2 using KVM_SET_VCPU_EVENTS, it is expected to set
+exception.has_payload and to put the faulting address (or the new DR6
+bits*) in the exception_payload field.
+
+This capability also enables exception.pending in struct
+kvm_vcpu_events, which allows userspace to distinguish between pending
+and injected exceptions.
+
+
+* For the new DR6 bits, note that bit 16 is set iff the #DB exception
+ will clear DR6.RTM.
+
8. Other capabilities.
----------------------
@@ -4772,3 +4888,10 @@ CPU when the exception is taken. If this virtual SError is taken to EL1 using
AArch64, this value will be reported in the ISS field of ESR_ELx.
See KVM_CAP_VCPU_EVENTS for more details.
+8.20 KVM_CAP_HYPERV_SEND_IPI
+
+Architectures: x86
+
+This capability indicates that KVM supports paravirtualized Hyper-V IPI send
+hypercalls:
+HvCallSendSyntheticClusterIpi, HvCallSendSyntheticClusterIpiEx.