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authorLinus Torvalds <torvalds@linux-foundation.org>2022-10-09 19:39:55 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-10-09 19:39:55 +0300
commitef688f8b8cd3eb20547a6543f03e3d8952b87769 (patch)
treed44f43e19e69bc7828a16a259dd7f42afca02e99 /Documentation
parent0e470763d84dcad27284067647dfb4b1a94dfce0 (diff)
parentc59fb127583869350256656b7ed848c398bef879 (diff)
downloadlinux-ef688f8b8cd3eb20547a6543f03e3d8952b87769.tar.xz
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini: "The first batch of KVM patches, mostly covering x86. ARM: - Account stage2 page table allocations in memory stats x86: - Account EPT/NPT arm64 page table allocations in memory stats - Tracepoint cleanups/fixes for nested VM-Enter and emulated MSR accesses - Drop eVMCS controls filtering for KVM on Hyper-V, all known versions of Hyper-V now support eVMCS fields associated with features that are enumerated to the guest - Use KVM's sanitized VMCS config as the basis for the values of nested VMX capabilities MSRs - A myriad event/exception fixes and cleanups. Most notably, pending exceptions morph into VM-Exits earlier, as soon as the exception is queued, instead of waiting until the next vmentry. This fixed a longstanding issue where the exceptions would incorrecly become double-faults instead of triggering a vmexit; the common case of page-fault vmexits had a special workaround, but now it's fixed for good - A handful of fixes for memory leaks in error paths - Cleanups for VMREAD trampoline and VMX's VM-Exit assembly flow - Never write to memory from non-sleepable kvm_vcpu_check_block() - Selftests refinements and cleanups - Misc typo cleanups Generic: - remove KVM_REQ_UNHALT" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (94 commits) KVM: remove KVM_REQ_UNHALT KVM: mips, x86: do not rely on KVM_REQ_UNHALT KVM: x86: never write to memory from kvm_vcpu_check_block() KVM: x86: Don't snapshot pending INIT/SIPI prior to checking nested events KVM: nVMX: Make event request on VMXOFF iff INIT/SIPI is pending KVM: nVMX: Make an event request if INIT or SIPI is pending on VM-Enter KVM: SVM: Make an event request if INIT or SIPI is pending when GIF is set KVM: x86: lapic does not have to process INIT if it is blocked KVM: x86: Rename kvm_apic_has_events() to make it INIT/SIPI specific KVM: x86: Rename and expose helper to detect if INIT/SIPI are allowed KVM: nVMX: Make an event request when pending an MTF nested VM-Exit KVM: x86: make vendor code check for all nested events mailmap: Update Oliver's email address KVM: x86: Allow force_emulation_prefix to be written without a reload KVM: selftests: Add an x86-only test to verify nested exception queueing KVM: selftests: Use uapi header to get VMX and SVM exit reasons/codes KVM: x86: Rename inject_pending_events() to kvm_check_and_inject_events() KVM: VMX: Update MTF and ICEBP comments to document KVM's subtle behavior KVM: x86: Treat pending TRIPLE_FAULT requests as pending exceptions KVM: x86: Morph pending exceptions to pending VM-Exits at queue time ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/admin-guide/cgroup-v2.rst5
-rw-r--r--Documentation/filesystems/proc.rst4
-rw-r--r--Documentation/virt/kvm/api.rst113
-rw-r--r--Documentation/virt/kvm/vcpu-requests.rst28
4 files changed, 16 insertions, 134 deletions
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index be4a77baf784..7ce8130a8924 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -1355,6 +1355,11 @@ PAGE_SIZE multiple when read back.
pagetables
Amount of memory allocated for page tables.
+ sec_pagetables
+ Amount of memory allocated for secondary page tables,
+ this currently includes KVM mmu allocations on x86
+ and arm64.
+
percpu (npn)
Amount of memory used for storing per-cpu kernel
data structures.
diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index e7aafc82be99..898c99eae8e4 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -982,6 +982,7 @@ Example output. You may not have all of these fields.
SUnreclaim: 142336 kB
KernelStack: 11168 kB
PageTables: 20540 kB
+ SecPageTables: 0 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
@@ -1090,6 +1091,9 @@ KernelStack
Memory consumed by the kernel stacks of all tasks
PageTables
Memory consumed by userspace page tables
+SecPageTables
+ Memory consumed by secondary page tables, this currently
+ currently includes KVM mmu allocations on x86 and arm64.
NFS_Unstable
Always zero. Previous counted pages which had been written to
the server, but has not been committed to stable storage.
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index abd7c32126ce..236a797be71c 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -4074,7 +4074,7 @@ Queues an SMI on the thread's vcpu.
4.97 KVM_X86_SET_MSR_FILTER
----------------------------
-:Capability: KVM_X86_SET_MSR_FILTER
+:Capability: KVM_CAP_X86_MSR_FILTER
:Architectures: x86
:Type: vm ioctl
:Parameters: struct kvm_msr_filter
@@ -4173,8 +4173,10 @@ If an MSR access is not permitted through the filtering, it generates a
allows user space to deflect and potentially handle various MSR accesses
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.
+Note, invoking this ioctl while a vCPU is running is inherently racy. However,
+KVM does guarantee that vCPUs will see either the previous filter or the new
+filter, e.g. MSRs with identical settings in both the old and new filter will
+have deterministic behavior.
4.98 KVM_CREATE_SPAPR_TCE_64
----------------------------
@@ -5287,110 +5289,7 @@ KVM_PV_DUMP
authentication tag all of which are needed to decrypt the dump at a
later time.
-
-4.126 KVM_X86_SET_MSR_FILTER
-----------------------------
-
-:Capability: KVM_CAP_X86_MSR_FILTER
-:Architectures: x86
-:Type: vm ioctl
-:Parameters: struct kvm_msr_filter
-:Returns: 0 on success, < 0 on error
-
-::
-
- struct kvm_msr_filter_range {
- #define KVM_MSR_FILTER_READ (1 << 0)
- #define KVM_MSR_FILTER_WRITE (1 << 1)
- __u32 flags;
- __u32 nmsrs; /* number of msrs in bitmap */
- __u32 base; /* MSR index the bitmap starts at */
- __u8 *bitmap; /* a 1 bit allows the operations in flags, 0 denies */
- };
-
- #define KVM_MSR_FILTER_MAX_RANGES 16
- struct kvm_msr_filter {
- #define KVM_MSR_FILTER_DEFAULT_ALLOW (0 << 0)
- #define KVM_MSR_FILTER_DEFAULT_DENY (1 << 0)
- __u32 flags;
- struct kvm_msr_filter_range ranges[KVM_MSR_FILTER_MAX_RANGES];
- };
-
-flags values for ``struct kvm_msr_filter_range``:
-
-``KVM_MSR_FILTER_READ``
-
- Filter read accesses to MSRs using the given bitmap. A 0 in the bitmap
- indicates that a read should immediately fail, while a 1 indicates that
- a read for a particular MSR should be handled regardless of the default
- filter action.
-
-``KVM_MSR_FILTER_WRITE``
-
- Filter write accesses to MSRs using the given bitmap. A 0 in the bitmap
- indicates that a write should immediately fail, while a 1 indicates that
- a write for a particular MSR should be handled regardless of the default
- filter action.
-
-``KVM_MSR_FILTER_READ | KVM_MSR_FILTER_WRITE``
-
- Filter both read and write accesses to MSRs using the given bitmap. A 0
- in the bitmap indicates that both reads and writes should immediately fail,
- while a 1 indicates that reads and writes for a particular MSR are not
- filtered by this range.
-
-flags values for ``struct kvm_msr_filter``:
-
-``KVM_MSR_FILTER_DEFAULT_ALLOW``
-
- If no filter range matches an MSR index that is getting accessed, KVM will
- fall back to allowing access to the MSR.
-
-``KVM_MSR_FILTER_DEFAULT_DENY``
-
- If no filter range matches an MSR index that is getting accessed, KVM will
- fall back to rejecting access to the MSR. In this mode, all MSRs that should
- be processed by KVM need to explicitly be marked as allowed in the bitmaps.
-
-This ioctl allows user space to define up to 16 bitmaps of MSR ranges to
-specify whether a certain MSR access should be explicitly filtered for or not.
-
-If this ioctl has never been invoked, MSR accesses are not guarded and the
-default KVM in-kernel emulation behavior is fully preserved.
-
-Calling this ioctl with an empty set of ranges (all nmsrs == 0) disables MSR
-filtering. In that mode, ``KVM_MSR_FILTER_DEFAULT_DENY`` is invalid and causes
-an error.
-
-As soon as the filtering is in place, every MSR access is processed through
-the filtering except for accesses to the x2APIC MSRs (from 0x800 to 0x8ff);
-x2APIC MSRs are always allowed, independent of the ``default_allow`` setting,
-and their behavior depends on the ``X2APIC_ENABLE`` bit of the APIC base
-register.
-
-If a bit is within one of the defined ranges, read and write accesses are
-guarded by the bitmap's value for the MSR index if the kind of access
-is included in the ``struct kvm_msr_filter_range`` flags. If no range
-cover this particular access, the behavior is determined by the flags
-field in the kvm_msr_filter struct: ``KVM_MSR_FILTER_DEFAULT_ALLOW``
-and ``KVM_MSR_FILTER_DEFAULT_DENY``.
-
-Each bitmap range specifies a range of MSRs to potentially allow access on.
-The range goes from MSR index [base .. base+nmsrs]. The flags field
-indicates whether reads, writes or both reads and writes are filtered
-by setting a 1 bit in the bitmap for the corresponding MSR index.
-
-If an MSR access is not permitted through the filtering, it generates a
-#GP inside the guest. When combined with KVM_CAP_X86_USER_SPACE_MSR, that
-allows user space to deflect and potentially handle various MSR accesses
-into user space.
-
-Note, invoking this ioctl with a vCPU is running is inherently racy. However,
-KVM does guarantee that vCPUs will see either the previous filter or the new
-filter, e.g. MSRs with identical settings in both the old and new filter will
-have deterministic behavior.
-
-4.127 KVM_XEN_HVM_SET_ATTR
+4.126 KVM_XEN_HVM_SET_ATTR
--------------------------
:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
diff --git a/Documentation/virt/kvm/vcpu-requests.rst b/Documentation/virt/kvm/vcpu-requests.rst
index 31f62b64e07b..87f04c1fa53d 100644
--- a/Documentation/virt/kvm/vcpu-requests.rst
+++ b/Documentation/virt/kvm/vcpu-requests.rst
@@ -97,7 +97,7 @@ VCPU requests are simply bit indices of the ``vcpu->requests`` bitmap.
This means general bitops, like those documented in [atomic-ops]_ could
also be used, e.g. ::
- clear_bit(KVM_REQ_UNHALT & KVM_REQUEST_MASK, &vcpu->requests);
+ clear_bit(KVM_REQ_UNBLOCK & KVM_REQUEST_MASK, &vcpu->requests);
However, VCPU request users should refrain from doing so, as it would
break the abstraction. The first 8 bits are reserved for architecture
@@ -126,17 +126,6 @@ KVM_REQ_UNBLOCK
or in order to update the interrupt routing and ensure that assigned
devices will wake up the vCPU.
-KVM_REQ_UNHALT
-
- This request may be made from the KVM common function kvm_vcpu_block(),
- which is used to emulate an instruction that causes a CPU to halt until
- one of an architectural specific set of events and/or interrupts is
- received (determined by checking kvm_arch_vcpu_runnable()). When that
- event or interrupt arrives kvm_vcpu_block() makes the request. This is
- in contrast to when kvm_vcpu_block() returns due to any other reason,
- such as a pending signal, which does not indicate the VCPU's halt
- emulation should stop, and therefore does not make the request.
-
KVM_REQ_OUTSIDE_GUEST_MODE
This "request" ensures the target vCPU has exited guest mode prior to the
@@ -297,21 +286,6 @@ architecture dependent. kvm_vcpu_block() calls kvm_arch_vcpu_runnable()
to check if it should awaken. One reason to do so is to provide
architectures a function where requests may be checked if necessary.
-Clearing Requests
------------------
-
-Generally it only makes sense for the receiving VCPU thread to clear a
-request. However, in some circumstances, such as when the requesting
-thread and the receiving VCPU thread are executed serially, such as when
-they are the same thread, or when they are using some form of concurrency
-control to temporarily execute synchronously, then it's possible to know
-that the request may be cleared immediately, rather than waiting for the
-receiving VCPU thread to handle the request in VCPU RUN. The only current
-examples of this are kvm_vcpu_block() calls made by VCPUs to block
-themselves. A possible side-effect of that call is to make the
-KVM_REQ_UNHALT request, which may then be cleared immediately when the
-VCPU returns from the call.
-
References
==========