blaster4385/linux-IllusionX/virt, branch v6.12.1

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2024-10-21T18:22:04Z

Pull kvm fixes from Paolo Bonzini: "ARM64: - Fix the guest view of the ID registers, making the relevant fields writable from userspace (affecting ID_AA64DFR0_EL1 and ID_AA64PFR1_EL1) - Correcly expose S1PIE to guests, fixing a regression introduced in 6.12-rc1 with the S1POE support - Fix the recycling of stage-2 shadow MMUs by tracking the context (are we allowed to block or not) as well as the recycling state - Address a couple of issues with the vgic when userspace misconfigures the emulation, resulting in various splats. Headaches courtesy of our Syzkaller friends - Stop wasting space in the HYP idmap, as we are dangerously close to the 4kB limit, and this has already exploded in -next - Fix another race in vgic_init() - Fix a UBSAN error when faking the cache topology with MTE enabled RISCV: - RISCV: KVM: use raw_spinlock for critical section in imsic x86: - A bandaid for lack of XCR0 setup in selftests, which causes trouble if the compiler is configured to have x86-64-v3 (with AVX) as the default ISA. Proper XCR0 setup will come in the next merge window. - Fix an issue where KVM would not ignore low bits of the nested CR3 and potentially leak up to 31 bytes out of the guest memory's bounds - Fix case in which an out-of-date cached value for the segments could by returned by KVM_GET_SREGS. - More cleanups for KVM_X86_QUIRK_SLOT_ZAP_ALL - Override MTRR state for KVM confidential guests, making it WB by default as is already the case for Hyper-V guests. Generic: - Remove a couple of unused functions" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (27 commits) RISCV: KVM: use raw_spinlock for critical section in imsic KVM: selftests: Fix out-of-bounds reads in CPUID test's array lookups KVM: selftests: x86: Avoid using SSE/AVX instructions KVM: nSVM: Ignore nCR3[4:0] when loading PDPTEs from memory KVM: VMX: reset the segment cache after segment init in vmx_vcpu_reset() KVM: x86: Clean up documentation for KVM_X86_QUIRK_SLOT_ZAP_ALL KVM: x86/mmu: Add lockdep assert to enforce safe usage of kvm_unmap_gfn_range() KVM: x86/mmu: Zap only SPs that shadow gPTEs when deleting memslot x86/kvm: Override default caching mode for SEV-SNP and TDX KVM: Remove unused kvm_vcpu_gfn_to_pfn_atomic KVM: Remove unused kvm_vcpu_gfn_to_pfn KVM: arm64: Ensure vgic_ready() is ordered against MMIO registration KVM: arm64: vgic: Don't check for vgic_ready() when setting NR_IRQS KVM: arm64: Fix shift-out-of-bounds bug KVM: arm64: Shave a few bytes from the EL2 idmap code KVM: arm64: Don't eagerly teardown the vgic on init error KVM: arm64: Expose S1PIE to guests KVM: arm64: nv: Clarify safety of allowing TLBI unmaps to reschedule KVM: arm64: nv: Punt stage-2 recycling to a vCPU request KVM: arm64: nv: Do not block when unmapping stage-2 if disallowed ...

KVM: Remove unused kvm_vcpu_gfn_to_pfn_atomic

2024-10-20T11:05:51Z

The last use of kvm_vcpu_gfn_to_pfn_atomic was removed by commit 1bbc60d0c7e5 ("KVM: x86/mmu: Remove MMU auditing") Remove it. Signed-off-by: Dr. David Alan Gilbert Message-ID: <20241001141354.18009-3-linux@treblig.org> [Adjust Documentation/virt/kvm/locking.rst. - Paolo] Signed-off-by: Paolo Bonzini

KVM: Remove unused kvm_vcpu_gfn_to_pfn

2024-10-20T11:04:52Z

The last use of kvm_vcpu_gfn_to_pfn was removed by commit b1624f99aa8f ("KVM: Remove kvm_vcpu_gfn_to_page() and kvm_vcpu_gpa_to_page()") Remove it. Signed-off-by: Dr. David Alan Gilbert Message-ID: <20241001141354.18009-2-linux@treblig.org> Signed-off-by: Paolo Bonzini

sched/fair: Fix external p->on_rq users

2024-10-14T07:14:35Z

Sean noted that ever since commit 152e11f6df29 ("sched/fair: Implement delayed dequeue") KVM's preemption notifiers have started mis-classifying preemption vs blocking. Notably p->on_rq is no longer sufficient to determine if a task is runnable or blocked -- the aforementioned commit introduces tasks that remain on the runqueue even through they will not run again, and should be considered blocked for many cases. Add the task_is_runnable() helper to classify things and audit all external users of the p->on_rq state. Also add a few comments. Fixes: 152e11f6df29 ("sched/fair: Implement delayed dequeue") Reported-by: Sean Christopherson Tested-by: Sean Christopherson Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lkml.kernel.org/r/20241010091843.GK33184@noisy.programming.kicks-ass.net

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2024-09-28T16:20:14Z

Pull x86 kvm updates from Paolo Bonzini: "x86: - KVM currently invalidates the entirety of the page tables, not just those for the memslot being touched, when a memslot is moved or deleted. This does not traditionally have particularly noticeable overhead, but Intel's TDX will require the guest to re-accept private pages if they are dropped from the secure EPT, which is a non starter. Actually, the only reason why this is not already being done is a bug which was never fully investigated and caused VM instability with assigned GeForce GPUs, so allow userspace to opt into the new behavior. - Advertise AVX10.1 to userspace (effectively prep work for the "real" AVX10 functionality that is on the horizon) - Rework common MSR handling code to suppress errors on userspace accesses to unsupported-but-advertised MSRs This will allow removing (almost?) all of KVM's exemptions for userspace access to MSRs that shouldn't exist based on the vCPU model (the actual cleanup is non-trivial future work) - Rework KVM's handling of x2APIC ICR, again, because AMD (x2AVIC) splits the 64-bit value into the legacy ICR and ICR2 storage, whereas Intel (APICv) stores the entire 64-bit value at the ICR offset - Fix a bug where KVM would fail to exit to userspace if one was triggered by a fastpath exit handler - Add fastpath handling of HLT VM-Exit to expedite re-entering the guest when there's already a pending wake event at the time of the exit - Fix a WARN caused by RSM entering a nested guest from SMM with invalid guest state, by forcing the vCPU out of guest mode prior to signalling SHUTDOWN (the SHUTDOWN hits the VM altogether, not the nested guest) - Overhaul the "unprotect and retry" logic to more precisely identify cases where retrying is actually helpful, and to harden all retry paths against putting the guest into an infinite retry loop - Add support for yielding, e.g. to honor NEED_RESCHED, when zapping rmaps in the shadow MMU - Refactor pieces of the shadow MMU related to aging SPTEs in prepartion for adding multi generation LRU support in KVM - Don't stuff the RSB after VM-Exit when RETPOLINE=y and AutoIBRS is enabled, i.e. when the CPU has already flushed the RSB - Trace the per-CPU host save area as a VMCB pointer to improve readability and cleanup the retrieval of the SEV-ES host save area - Remove unnecessary accounting of temporary nested VMCB related allocations - Set FINAL/PAGE in the page fault error code for EPT violations if and only if the GVA is valid. If the GVA is NOT valid, there is no guest-side page table walk and so stuffing paging related metadata is nonsensical - Fix a bug where KVM would incorrectly synthesize a nested VM-Exit instead of emulating posted interrupt delivery to L2 - Add a lockdep assertion to detect unsafe accesses of vmcs12 structures - Harden eVMCS loading against an impossible NULL pointer deref (really truly should be impossible) - Minor SGX fix and a cleanup - Misc cleanups Generic: - Register KVM's cpuhp and syscore callbacks when enabling virtualization in hardware, as the sole purpose of said callbacks is to disable and re-enable virtualization as needed - Enable virtualization when KVM is loaded, not right before the first VM is created Together with the previous change, this simplifies a lot the logic of the callbacks, because their very existence implies virtualization is enabled - Fix a bug that results in KVM prematurely exiting to userspace for coalesced MMIO/PIO in many cases, clean up the related code, and add a testcase - Fix a bug in kvm_clear_guest() where it would trigger a buffer overflow _if_ the gpa+len crosses a page boundary, which thankfully is guaranteed to not happen in the current code base. Add WARNs in more helpers that read/write guest memory to detect similar bugs Selftests: - Fix a goof that caused some Hyper-V tests to be skipped when run on bare metal, i.e. NOT in a VM - Add a regression test for KVM's handling of SHUTDOWN for an SEV-ES guest - Explicitly include one-off assets in .gitignore. Past Sean was completely wrong about not being able to detect missing .gitignore entries - Verify userspace single-stepping works when KVM happens to handle a VM-Exit in its fastpath - Misc cleanups" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (127 commits) Documentation: KVM: fix warning in "make htmldocs" s390: Enable KVM_S390_UCONTROL config in debug_defconfig selftests: kvm: s390: Add VM run test case KVM: SVM: let alternatives handle the cases when RSB filling is required KVM: VMX: Set PFERR_GUEST_{FINAL,PAGE}_MASK if and only if the GVA is valid KVM: x86/mmu: Use KVM_PAGES_PER_HPAGE() instead of an open coded equivalent KVM: x86/mmu: Add KVM_RMAP_MANY to replace open coded '1' and '1ul' literals KVM: x86/mmu: Fold mmu_spte_age() into kvm_rmap_age_gfn_range() KVM: x86/mmu: Morph kvm_handle_gfn_range() into an aging specific helper KVM: x86/mmu: Honor NEED_RESCHED when zapping rmaps and blocking is allowed KVM: x86/mmu: Add a helper to walk and zap rmaps for a memslot KVM: x86/mmu: Plumb a @can_yield parameter into __walk_slot_rmaps() KVM: x86/mmu: Move walk_slot_rmaps() up near for_each_slot_rmap_range() KVM: x86/mmu: WARN on MMIO cache hit when emulating write-protected gfn KVM: x86/mmu: Detect if unprotect will do anything based on invalid_list KVM: x86/mmu: Subsume kvm_mmu_unprotect_page() into the and_retry() version KVM: x86: Rename reexecute_instruction()=>kvm_unprotect_and_retry_on_failure() KVM: x86: Update retry protection fields when forcing retry on emulation failure KVM: x86: Apply retry protection to "unprotect on failure" path KVM: x86: Check EMULTYPE_WRITE_PF_TO_SP before unprotecting gfn ...

[tree-wide] finally take no_llseek out

2024-09-27T15:18:43Z

no_llseek had been defined to NULL two years ago, in commit 868941b14441 ("fs: remove no_llseek") To quote that commit, At -rc1 we'll need do a mechanical removal of no_llseek - git grep -l -w no_llseek | grep -v porting.rst | while read i; do sed -i '/\/d' $i done would do it. Unfortunately, that hadn't been done. Linus, could you do that now, so that we could finally put that thing to rest? All instances are of the form .llseek = no_llseek, so it's obviously safe. Signed-off-by: Al Viro Signed-off-by: Linus Torvalds

Merge tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2024-09-23T16:35:36Z

Pull 'struct fd' updates from Al Viro: "Just the 'struct fd' layout change, with conversion to accessor helpers" * tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: add struct fd constructors, get rid of __to_fd() struct fd: representation change introduce fd_file(), convert all accessors to it.

Merge tag 'kvm-x86-generic-6.12' of https://github.com/kvm-x86/linux into HEAD

2024-09-17T15:38:22Z

KVK generic changes for 6.12: - Fix a bug that results in KVM prematurely exiting to userspace for coalesced MMIO/PIO in many cases, clean up the related code, and add a testcase. - Fix a bug in kvm_clear_guest() where it would trigger a buffer overflow _if_ the gpa+len crosses a page boundary, which thankfully is guaranteed to not happen in the current code base. Add WARNs in more helpers that read/write guest memory to detect similar bugs.

KVM: use follow_pfnmap API

2024-09-17T08:06:59Z

Use the new pfnmap API to allow huge MMIO mappings for VMs. The rest work is done perfectly on the other side (host_pfn_mapping_level()). Link: https://lkml.kernel.org/r/20240826204353.2228736-11-peterx@redhat.com Signed-off-by: Peter Xu Cc: Paolo Bonzini Cc: Sean Christopherson Cc: Alexander Gordeev Cc: Alex Williamson Cc: Aneesh Kumar K.V Cc: Borislav Petkov Cc: Catalin Marinas Cc: Christian Borntraeger Cc: Dave Hansen Cc: David Hildenbrand Cc: Gavin Shan Cc: Gerald Schaefer Cc: Heiko Carstens Cc: Ingo Molnar Cc: Jason Gunthorpe Cc: Matthew Wilcox Cc: Niklas Schnelle Cc: Ryan Roberts Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Will Deacon Cc: Zi Yan Signed-off-by: Andrew Morton

KVM: Harden guest memory APIs against out-of-bounds accesses

2024-09-10T03:15:34Z

When reading or writing a guest page, WARN and bail if offset+len would result in a read to a different page so that KVM bugs are more likely to be detected, and so that any such bugs are less likely to escalate to an out-of-bounds access. E.g. if userspace isn't using guard pages and the target page is at the end of a memslot. Note, KVM already hardens itself in similar APIs, e.g. in the "cached" variants, it's just the vanilla APIs that are playing with fire. Link: https://lore.kernel.org/r/20240829191413.900740-3-seanjc@google.com Signed-off-by: Sean Christopherson