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authorLinus Torvalds <torvalds@linux-foundation.org>2023-07-04 00:32:22 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2023-07-04 00:32:22 +0200
commite8069f5a8e3bdb5fdeeff895780529388592ee7a (patch)
treece35ab85db9b66a7e488707fccdb33ce54f696dd /Documentation/virt
parentMerge tag 'kgdb-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dan... (diff)
parentMerge tag 'kvm-x86-vmx-6.5' of https://github.com/kvm-x86/linux into HEAD (diff)
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini: "ARM64: - Eager page splitting optimization for dirty logging, optionally allowing for a VM to avoid the cost of hugepage splitting in the stage-2 fault path. - Arm FF-A proxy for pKVM, allowing a pKVM host to safely interact with services that live in the Secure world. pKVM intervenes on FF-A calls to guarantee the host doesn't misuse memory donated to the hyp or a pKVM guest. - Support for running the split hypervisor with VHE enabled, known as 'hVHE' mode. This is extremely useful for testing the split hypervisor on VHE-only systems, and paves the way for new use cases that depend on having two TTBRs available at EL2. - Generalized framework for configurable ID registers from userspace. KVM/arm64 currently prevents arbitrary CPU feature set configuration from userspace, but the intent is to relax this limitation and allow userspace to select a feature set consistent with the CPU. - Enable the use of Branch Target Identification (FEAT_BTI) in the hypervisor. - Use a separate set of pointer authentication keys for the hypervisor when running in protected mode, as the host is untrusted at runtime. - Ensure timer IRQs are consistently released in the init failure paths. - Avoid trapping CTR_EL0 on systems with Enhanced Virtualization Traps (FEAT_EVT), as it is a register commonly read from userspace. - Erratum workaround for the upcoming AmpereOne part, which has broken hardware A/D state management. RISC-V: - Redirect AMO load/store misaligned traps to KVM guest - Trap-n-emulate AIA in-kernel irqchip for KVM guest - Svnapot support for KVM Guest s390: - New uvdevice secret API - CMM selftest and fixes - fix racy access to target CPU for diag 9c x86: - Fix missing/incorrect #GP checks on ENCLS - Use standard mmu_notifier hooks for handling APIC access page - Drop now unnecessary TR/TSS load after VM-Exit on AMD - Print more descriptive information about the status of SEV and SEV-ES during module load - Add a test for splitting and reconstituting hugepages during and after dirty logging - Add support for CPU pinning in demand paging test - Add support for AMD PerfMonV2, with a variety of cleanups and minor fixes included along the way - Add a "nx_huge_pages=never" option to effectively avoid creating NX hugepage recovery threads (because nx_huge_pages=off can be toggled at runtime) - Move handling of PAT out of MTRR code and dedup SVM+VMX code - Fix output of PIC poll command emulation when there's an interrupt - Add a maintainer's handbook to document KVM x86 processes, preferred coding style, testing expectations, etc. - Misc cleanups, fixes and comments Generic: - Miscellaneous bugfixes and cleanups Selftests: - Generate dependency files so that partial rebuilds work as expected" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (153 commits) Documentation/process: Add a maintainer handbook for KVM x86 Documentation/process: Add a label for the tip tree handbook's coding style KVM: arm64: Fix misuse of KVM_ARM_VCPU_POWER_OFF bit index RISC-V: KVM: Remove unneeded semicolon RISC-V: KVM: Allow Svnapot extension for Guest/VM riscv: kvm: define vcpu_sbi_ext_pmu in header RISC-V: KVM: Expose IMSIC registers as attributes of AIA irqchip RISC-V: KVM: Add in-kernel virtualization of AIA IMSIC RISC-V: KVM: Expose APLIC registers as attributes of AIA irqchip RISC-V: KVM: Add in-kernel emulation of AIA APLIC RISC-V: KVM: Implement device interface for AIA irqchip RISC-V: KVM: Skeletal in-kernel AIA irqchip support RISC-V: KVM: Set kvm_riscv_aia_nr_hgei to zero RISC-V: KVM: Add APLIC related defines RISC-V: KVM: Add IMSIC related defines RISC-V: KVM: Implement guest external interrupt line management KVM: x86: Remove PRIx* definitions as they are solely for user space s390/uv: Update query for secret-UVCs s390/uv: replace scnprintf with sysfs_emit s390/uvdevice: Add 'Lock Secret Store' UVC ...
Diffstat (limited to 'Documentation/virt')
-rw-r--r--Documentation/virt/kvm/api.rst27
-rw-r--r--Documentation/virt/kvm/x86/mmu.rst2
2 files changed, 28 insertions, 1 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 96c4475539c2..c0ddd3035462 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -8445,6 +8445,33 @@ structure.
When getting the Modified Change Topology Report value, the attr->addr
must point to a byte where the value will be stored or retrieved from.
+8.40 KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE
+---------------------------------------
+
+:Capability: KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE
+:Architectures: arm64
+:Type: vm
+:Parameters: arg[0] is the new split chunk size.
+:Returns: 0 on success, -EINVAL if any memslot was already created.
+
+This capability sets the chunk size used in Eager Page Splitting.
+
+Eager Page Splitting improves the performance of dirty-logging (used
+in live migrations) when guest memory is backed by huge-pages. It
+avoids splitting huge-pages (into PAGE_SIZE pages) on fault, by doing
+it eagerly when enabling dirty logging (with the
+KVM_MEM_LOG_DIRTY_PAGES flag for a memory region), or when using
+KVM_CLEAR_DIRTY_LOG.
+
+The chunk size specifies how many pages to break at a time, using a
+single allocation for each chunk. Bigger the chunk size, more pages
+need to be allocated ahead of time.
+
+The chunk size needs to be a valid block size. The list of acceptable
+block sizes is exposed in KVM_CAP_ARM_SUPPORTED_BLOCK_SIZES as a
+64-bit bitmap (each bit describing a block size). The default value is
+0, to disable the eager page splitting.
+
9. Known KVM API problems
=========================
diff --git a/Documentation/virt/kvm/x86/mmu.rst b/Documentation/virt/kvm/x86/mmu.rst
index 8364afa228ec..26f62034b6f3 100644
--- a/Documentation/virt/kvm/x86/mmu.rst
+++ b/Documentation/virt/kvm/x86/mmu.rst
@@ -205,7 +205,7 @@ Shadow pages contain the following information:
role.passthrough:
The page is not backed by a guest page table, but its first entry
points to one. This is set if NPT uses 5-level page tables (host
- CR4.LA57=1) and is shadowing L1's 4-level NPT (L1 CR4.LA57=1).
+ CR4.LA57=1) and is shadowing L1's 4-level NPT (L1 CR4.LA57=0).
gfn:
Either the guest page table containing the translations shadowed by this
page, or the base page frame for linear translations. See role.direct.