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2020-12-04kvm: x86/mmu: Use cpuid to determine max gfnRick Edgecombe
In the TDP MMU, use shadow_phys_bits to dermine the maximum possible GFN mapped in the guest for zapping operations. boot_cpu_data.x86_phys_bits may be reduced in the case of HW features that steal HPA bits for other purposes. However, this doesn't necessarily reduce GPA space that can be accessed via TDP. So zap based on a maximum gfn calculated with MAXPHYADDR retrieved from CPUID. This is already stored in shadow_phys_bits, so use it instead of x86_phys_bits. Fixes: faaf05b00aec ("kvm: x86/mmu: Support zapping SPTEs in the TDP MMU") Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Message-Id: <20201203231120.27307-1-rick.p.edgecombe@intel.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-04kvm: svm: de-allocate svm_cpu_data for all cpus in svm_cpu_uninit()Jacob Xu
The cpu arg for svm_cpu_uninit() was previously ignored resulting in the per cpu structure svm_cpu_data not being de-allocated for all cpus. Signed-off-by: Jacob Xu <jacobhxu@google.com> Message-Id: <20201203205939.1783969-1-jacobhxu@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-27kvm: x86/mmu: Fix get_mmio_spte() on CPUs supporting 5-level PTVitaly Kuznetsov
Commit 95fb5b0258b7 ("kvm: x86/mmu: Support MMIO in the TDP MMU") caused the following WARNING on an Intel Ice Lake CPU: get_mmio_spte: detect reserved bits on spte, addr 0xb80a0, dump hierarchy: ------ spte 0xb80a0 level 5. ------ spte 0xfcd210107 level 4. ------ spte 0x1004c40107 level 3. ------ spte 0x1004c41107 level 2. ------ spte 0x1db00000000b83b6 level 1. WARNING: CPU: 109 PID: 10254 at arch/x86/kvm/mmu/mmu.c:3569 kvm_mmu_page_fault.cold.150+0x54/0x22f [kvm] ... Call Trace: ? kvm_io_bus_get_first_dev+0x55/0x110 [kvm] vcpu_enter_guest+0xaa1/0x16a0 [kvm] ? vmx_get_cs_db_l_bits+0x17/0x30 [kvm_intel] ? skip_emulated_instruction+0xaa/0x150 [kvm_intel] kvm_arch_vcpu_ioctl_run+0xca/0x520 [kvm] The guest triggering this crashes. Note, this happens with the traditional MMU and EPT enabled, not with the newly introduced TDP MMU. Turns out, there was a subtle change in the above mentioned commit. Previously, walk_shadow_page_get_mmio_spte() was setting 'root' to 'iterator.level' which is returned by shadow_walk_init() and this equals to 'vcpu->arch.mmu->shadow_root_level'. Now, get_mmio_spte() sets it to 'int root = vcpu->arch.mmu->root_level'. The difference between 'root_level' and 'shadow_root_level' on CPUs supporting 5-level page tables is that in some case we don't want to use 5-level, in particular when 'cpuid_maxphyaddr(vcpu) <= 48' kvm_mmu_get_tdp_level() returns '4'. In case upper layer is not used, the corresponding SPTE will fail '__is_rsvd_bits_set()' check. Revert to using 'shadow_root_level'. Fixes: 95fb5b0258b7 ("kvm: x86/mmu: Support MMIO in the TDP MMU") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20201126110206.2118959-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-27KVM: x86: Fix split-irqchip vs interrupt injection window requestPaolo Bonzini
kvm_cpu_accept_dm_intr and kvm_vcpu_ready_for_interrupt_injection are a hodge-podge of conditions, hacked together to get something that more or less works. But what is actually needed is much simpler; in both cases the fundamental question is, do we have a place to stash an interrupt if userspace does KVM_INTERRUPT? In userspace irqchip mode, that is !vcpu->arch.interrupt.injected. Currently kvm_event_needs_reinjection(vcpu) covers it, but it is unnecessarily restrictive. In split irqchip mode it's a bit more complicated, we need to check kvm_apic_accept_pic_intr(vcpu) (the IRQ window exit is basically an INTACK cycle and thus requires ExtINTs not to be masked) as well as !pending_userspace_extint(vcpu). However, there is no need to check kvm_event_needs_reinjection(vcpu), since split irqchip keeps pending ExtINT state separate from event injection state, and checking kvm_cpu_has_interrupt(vcpu) is wrong too since ExtINT has higher priority than APIC interrupts. In fact the latter fixes a bug: when userspace requests an IRQ window vmexit, an interrupt in the local APIC can cause kvm_cpu_has_interrupt() to be true and thus kvm_vcpu_ready_for_interrupt_injection() to return false. When this happens, vcpu_run does not exit to userspace but the interrupt window vmexits keep occurring. The VM loops without any hope of making progress. Once we try to fix these with something like return kvm_arch_interrupt_allowed(vcpu) && - !kvm_cpu_has_interrupt(vcpu) && - !kvm_event_needs_reinjection(vcpu) && - kvm_cpu_accept_dm_intr(vcpu); + (!lapic_in_kernel(vcpu) + ? !vcpu->arch.interrupt.injected + : (kvm_apic_accept_pic_intr(vcpu) + && !pending_userspace_extint(v))); we realize two things. First, thanks to the previous patch the complex conditional can reuse !kvm_cpu_has_extint(vcpu). Second, the interrupt window request in vcpu_enter_guest() bool req_int_win = dm_request_for_irq_injection(vcpu) && kvm_cpu_accept_dm_intr(vcpu); should be kept in sync with kvm_vcpu_ready_for_interrupt_injection(): it is unnecessary to ask the processor for an interrupt window if we would not be able to return to userspace. Therefore, kvm_cpu_accept_dm_intr(vcpu) is basically !kvm_cpu_has_extint(vcpu) ANDed with the existing check for masked ExtINT. It all makes sense: - we can accept an interrupt from userspace if there is a place to stash it (and, for irqchip split, ExtINTs are not masked). Interrupts from userspace _can_ be accepted even if right now EFLAGS.IF=0. - in order to tell userspace we will inject its interrupt ("IRQ window open" i.e. kvm_vcpu_ready_for_interrupt_injection), both KVM and the vCPU need to be ready to accept the interrupt. ... and this is what the patch implements. Reported-by: David Woodhouse <dwmw@amazon.co.uk> Analyzed-by: David Woodhouse <dwmw@amazon.co.uk> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nikos Tsironis <ntsironis@arrikto.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Tested-by: David Woodhouse <dwmw@amazon.co.uk>
2020-11-27KVM: x86: handle !lapic_in_kernel case in kvm_cpu_*_extintPaolo Bonzini
Centralize handling of interrupts from the userspace APIC in kvm_cpu_has_extint and kvm_cpu_get_extint, since userspace APIC interrupts are handled more or less the same as ExtINTs are with split irqchip. This removes duplicated code from kvm_cpu_has_injectable_intr and kvm_cpu_has_interrupt, and makes the code more similar between kvm_cpu_has_{extint,interrupt} on one side and kvm_cpu_get_{extint,interrupt} on the other. Cc: stable@vger.kernel.org Reviewed-by: Filippo Sironi <sironi@amazon.de> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Tested-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-17KVM: SVM: fix error return code in svm_create_vcpu()Chen Zhou
Fix to return a negative error code from the error handling case instead of 0 in function svm_create_vcpu(), as done elsewhere in this function. Fixes: f4c847a95654 ("KVM: SVM: refactor msr permission bitmap allocation") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Chen Zhou <chenzhou10@huawei.com> Message-Id: <20201117025426.167824-1-chenzhou10@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-16KVM: SVM: Fix offset computation bug in __sev_dbg_decrypt().Ashish Kalra
Fix offset computation in __sev_dbg_decrypt() to include the source paddr before it is rounded down to be aligned to 16 bytes as required by SEV API. This fixes incorrect guest memory dumps observed when using qemu monitor. Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> Message-Id: <20201110224205.29444-1-Ashish.Kalra@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-15kvm: mmu: fix is_tdp_mmu_check when the TDP MMU is not in usePaolo Bonzini
In some cases where shadow paging is in use, the root page will be either mmu->pae_root or vcpu->arch.mmu->lm_root. Then it will not have an associated struct kvm_mmu_page, because it is allocated with alloc_page instead of kvm_mmu_alloc_page. Just return false quickly from is_tdp_mmu_root if the TDP MMU is not in use, which also includes the case where shadow paging is enabled. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-13KVM: SVM: Update cr3_lm_rsvd_bits for AMD SEV guestsBabu Moger
For AMD SEV guests, update the cr3_lm_rsvd_bits to mask the memory encryption bit in reserved bits. Signed-off-by: Babu Moger <babu.moger@amd.com> Message-Id: <160521948301.32054.5783800787423231162.stgit@bmoger-ubuntu> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-13KVM: x86: Introduce cr3_lm_rsvd_bits in kvm_vcpu_archBabu Moger
SEV guests fail to boot on a system that supports the PCID feature. While emulating the RSM instruction, KVM reads the guest CR3 and calls kvm_set_cr3(). If the vCPU is in the long mode, kvm_set_cr3() does a sanity check for the CR3 value. In this case, it validates whether the value has any reserved bits set. The reserved bit range is 63:cpuid_maxphysaddr(). When AMD memory encryption is enabled, the memory encryption bit is set in the CR3 value. The memory encryption bit may fall within the KVM reserved bit range, causing the KVM emulation failure. Introduce a new field cr3_lm_rsvd_bits in kvm_vcpu_arch which will cache the reserved bits in the CR3 value. This will be initialized to rsvd_bits(cpuid_maxphyaddr(vcpu), 63). If the architecture has any special bits(like AMD SEV encryption bit) that needs to be masked from the reserved bits, should be cleared in vendor specific kvm_x86_ops.vcpu_after_set_cpuid handler. Fixes: a780a3ea628268b2 ("KVM: X86: Fix reserved bits check for MOV to CR3") Signed-off-by: Babu Moger <babu.moger@amd.com> Message-Id: <160521947657.32054.3264016688005356563.stgit@bmoger-ubuntu> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-13KVM: x86: clflushopt should be treated as a no-op by emulationDavid Edmondson
The instruction emulator ignores clflush instructions, yet fails to support clflushopt. Treat both similarly. Fixes: 13e457e0eebf ("KVM: x86: Emulator does not decode clflush well") Signed-off-by: David Edmondson <david.edmondson@oracle.com> Message-Id: <20201103120400.240882-1-david.edmondson@oracle.com> Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-08KVM: x86: handle MSR_IA32_DEBUGCTLMSR with report_ignored_msrsPankaj Gupta
Windows2016 guest tries to enable LBR by setting the corresponding bits in MSR_IA32_DEBUGCTLMSR. KVM does not emulate MSR_IA32_DEBUGCTLMSR and spams the host kernel logs with error messages like: kvm [...]: vcpu1, guest rIP: 0xfffff800a8b687d3 kvm_set_msr_common: MSR_IA32_DEBUGCTLMSR 0x1, nop" This patch fixes this by enabling error logging only with 'report_ignored_msrs=1'. Signed-off-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Message-Id: <20201105153932.24316-1-pankaj.gupta.linux@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-08kvm: x86: request masterclock update any time guest uses different msrOliver Upton
Commit 5b9bb0ebbcdc ("kvm: x86: encapsulate wrmsr(MSR_KVM_SYSTEM_TIME) emulation in helper fn", 2020-10-21) subtly changed the behavior of guest writes to MSR_KVM_SYSTEM_TIME(_NEW). Restore the previous behavior; update the masterclock any time the guest uses a different msr than before. Fixes: 5b9bb0ebbcdc ("kvm: x86: encapsulate wrmsr(MSR_KVM_SYSTEM_TIME) emulation in helper fn", 2020-10-21) Signed-off-by: Oliver Upton <oupton@google.com> Reviewed-by: Peter Shier <pshier@google.com> Message-Id: <20201027231044.655110-6-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-08kvm: x86: ensure pv_cpuid.features is initialized when enabling capOliver Upton
Make the paravirtual cpuid enforcement mechanism idempotent to ioctl() ordering by updating pv_cpuid.features whenever userspace requests the capability. Extract this update out of kvm_update_cpuid_runtime() into a new helper function and move its other call site into kvm_vcpu_after_set_cpuid() where it more likely belongs. Fixes: 66570e966dd9 ("kvm: x86: only provide PV features if enabled in guest's CPUID") Signed-off-by: Oliver Upton <oupton@google.com> Reviewed-by: Peter Shier <pshier@google.com> Message-Id: <20201027231044.655110-5-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-08kvm: x86: reads of restricted pv msrs should also result in #GPOliver Upton
commit 66570e966dd9 ("kvm: x86: only provide PV features if enabled in guest's CPUID") only protects against disallowed guest writes to KVM paravirtual msrs, leaving msr reads unchecked. Fix this by enforcing KVM_CPUID_FEATURES for msr reads as well. Fixes: 66570e966dd9 ("kvm: x86: only provide PV features if enabled in guest's CPUID") Signed-off-by: Oliver Upton <oupton@google.com> Reviewed-by: Peter Shier <pshier@google.com> Message-Id: <20201027231044.655110-4-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-08KVM: x86: use positive error values for msr emulation that causes #GPMaxim Levitsky
Recent introduction of the userspace msr filtering added code that uses negative error codes for cases that result in either #GP delivery to the guest, or handled by the userspace msr filtering. This breaks an assumption that a negative error code returned from the msr emulation code is a semi-fatal error which should be returned to userspace via KVM_RUN ioctl and usually kill the guest. Fix this by reusing the already existing KVM_MSR_RET_INVALID error code, and by adding a new KVM_MSR_RET_FILTERED error code for the userspace filtered msrs. Fixes: 291f35fb2c1d1 ("KVM: x86: report negative values from wrmsr emulation to userspace") Reported-by: Qian Cai <cai@redhat.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20201101115523.115780-1-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-08KVM: x86/mmu: fix counting of rmap entries in pte_list_addLi RongQing
Fix an off-by-one style bug in pte_list_add() where it failed to account the last full set of SPTEs, i.e. when desc->sptes is full and desc->more is NULL. Merge the two "PTE_LIST_EXT-1" checks as part of the fix to avoid an extra comparison. Signed-off-by: Li RongQing <lirongqing@baidu.com> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <1601196297-24104-1-git-send-email-lirongqing@baidu.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-31KVM: vmx: remove unused variablePaolo Bonzini
Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-31KVM: VMX: eVMCS: make evmcs_sanitize_exec_ctrls() work againVitaly Kuznetsov
It was noticed that evmcs_sanitize_exec_ctrls() is not being executed nowadays despite the code checking 'enable_evmcs' static key looking correct. Turns out, static key magic doesn't work in '__init' section (and it is unclear when things changed) but setup_vmcs_config() is called only once per CPU so we don't really need it to. Switch to checking 'enlightened_vmcs' instead, it is supposed to be in sync with 'enable_evmcs'. Opportunistically make evmcs_sanitize_exec_ctrls '__init' and drop unneeded extra newline from it. Reported-by: Yang Weijiang <weijiang.yang@intel.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20201014143346.2430936-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-30KVM: x86: Fix NULL dereference at kvm_msr_ignored_check()Takashi Iwai
The newly introduced kvm_msr_ignored_check() tries to print error or debug messages via vcpu_*() macros, but those may cause Oops when NULL vcpu is passed for KVM_GET_MSRS ioctl. Fix it by replacing the print calls with kvm_*() macros. (Note that this will leave vcpu argument completely unused in the function, but I didn't touch it to make the fix as small as possible. A clean up may be applied later.) Fixes: 12bc2132b15e ("KVM: X86: Do the same ignore_msrs check for feature msrs") BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1178280 Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Message-Id: <20201030151414.20165-1-tiwai@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-30KVM: x86: replace static const variables with macrosPaolo Bonzini
Even though the compiler is able to replace static const variables with their value, it will warn about them being unused when Linux is built with W=1. Use good old macros instead, this is not C++. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-24Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Paolo Bonzini: "Two fixes for this merge window, and an unrelated bugfix for a host hang" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: ioapic: break infinite recursion on lazy EOI KVM: vmx: rename pi_init to avoid conflict with paride KVM: x86/mmu: Avoid modulo operator on 64-bit value to fix i386 build
2020-10-24KVM: ioapic: break infinite recursion on lazy EOIVitaly Kuznetsov
During shutdown the IOAPIC trigger mode is reset to edge triggered while the vfio-pci INTx is still registered with a resampler. This allows us to get into an infinite loop: ioapic_set_irq -> ioapic_lazy_update_eoi -> kvm_ioapic_update_eoi_one -> kvm_notify_acked_irq -> kvm_notify_acked_gsi -> (via irq_acked fn ptr) irqfd_resampler_ack -> kvm_set_irq -> (via set fn ptr) kvm_set_ioapic_irq -> kvm_ioapic_set_irq -> ioapic_set_irq Commit 8be8f932e3db ("kvm: ioapic: Restrict lazy EOI update to edge-triggered interrupts", 2020-05-04) acknowledges that this recursion loop exists and tries to avoid it at the call to ioapic_lazy_update_eoi, but at this point the scenario is already set, we have an edge interrupt with resampler on the same gsi. Fortunately, the only user of irq ack notifiers (in addition to resamplefd) is i8254 timer interrupt reinjection. These are edge-triggered, so in principle they would need the call to kvm_ioapic_update_eoi_one from ioapic_lazy_update_eoi, but they already disable AVIC(*), so they don't need the lazy EOI behavior. Therefore, remove the call to kvm_ioapic_update_eoi_one from ioapic_lazy_update_eoi. This fixes CVE-2020-27152. Note that this issue cannot happen with SR-IOV assigned devices because virtual functions do not have INTx, only MSI. Fixes: f458d039db7e ("kvm: ioapic: Lazy update IOAPIC EOI") Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Tested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-24KVM: vmx: rename pi_init to avoid conflict with paridePaolo Bonzini
allyesconfig results in: ld: drivers/block/paride/paride.o: in function `pi_init': (.text+0x1340): multiple definition of `pi_init'; arch/x86/kvm/vmx/posted_intr.o:posted_intr.c:(.init.text+0x0): first defined here make: *** [Makefile:1164: vmlinux] Error 1 because commit: commit 8888cdd0996c2d51cd417f9a60a282c034f3fa28 Author: Xiaoyao Li <xiaoyao.li@intel.com> Date: Wed Sep 23 11:31:11 2020 -0700 KVM: VMX: Extract posted interrupt support to separate files added another pi_init(), though one already existed in the paride code. Reported-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-24KVM: x86/mmu: Avoid modulo operator on 64-bit value to fix i386 buildSean Christopherson
Replace a modulo operator with the more common pattern for computing the gfn "offset" of a huge page to fix an i386 build error. arch/x86/kvm/mmu/tdp_mmu.c:212: undefined reference to `__umoddi3' In fact, almost all of tdp_mmu.c can be elided on 32-bit builds, but that is a much larger patch. Fixes: 2f2fad0897cb ("kvm: x86/mmu: Add functions to handle changed TDP SPTEs") Reported-by: Daniel Díaz <daniel.diaz@linaro.org> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20201024031150.9318-1-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "For x86, there is a new alternative and (in the future) more scalable implementation of extended page tables that does not need a reverse map from guest physical addresses to host physical addresses. For now it is disabled by default because it is still lacking a few of the existing MMU's bells and whistles. However it is a very solid piece of work and it is already available for people to hammer on it. Other updates: ARM: - New page table code for both hypervisor and guest stage-2 - Introduction of a new EL2-private host context - Allow EL2 to have its own private per-CPU variables - Support of PMU event filtering - Complete rework of the Spectre mitigation PPC: - Fix for running nested guests with in-kernel IRQ chip - Fix race condition causing occasional host hard lockup - Minor cleanups and bugfixes x86: - allow trapping unknown MSRs to userspace - allow userspace to force #GP on specific MSRs - INVPCID support on AMD - nested AMD cleanup, on demand allocation of nested SVM state - hide PV MSRs and hypercalls for features not enabled in CPUID - new test for MSR_IA32_TSC writes from host and guest - cleanups: MMU, CPUID, shared MSRs - LAPIC latency optimizations ad bugfixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (232 commits) kvm: x86/mmu: NX largepage recovery for TDP MMU kvm: x86/mmu: Don't clear write flooding count for direct roots kvm: x86/mmu: Support MMIO in the TDP MMU kvm: x86/mmu: Support write protection for nesting in tdp MMU kvm: x86/mmu: Support disabling dirty logging for the tdp MMU kvm: x86/mmu: Support dirty logging for the TDP MMU kvm: x86/mmu: Support changed pte notifier in tdp MMU kvm: x86/mmu: Add access tracking for tdp_mmu kvm: x86/mmu: Support invalidate range MMU notifier for TDP MMU kvm: x86/mmu: Allocate struct kvm_mmu_pages for all pages in TDP MMU kvm: x86/mmu: Add TDP MMU PF handler kvm: x86/mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator arg kvm: x86/mmu: Support zapping SPTEs in the TDP MMU KVM: Cache as_id in kvm_memory_slot kvm: x86/mmu: Add functions to handle changed TDP SPTEs kvm: x86/mmu: Allocate and free TDP MMU roots kvm: x86/mmu: Init / Uninit the TDP MMU kvm: x86/mmu: Introduce tdp_iter KVM: mmu: extract spte.h and spte.c KVM: mmu: Separate updating a PTE from kvm_set_pte_rmapp ...
2020-10-23kvm: x86/mmu: NX largepage recovery for TDP MMUBen Gardon
When KVM maps a largepage backed region at a lower level in order to make it executable (i.e. NX large page shattering), it reduces the TLB performance of that region. In order to avoid making this degradation permanent, KVM must periodically reclaim shattered NX largepages by zapping them and allowing them to be rebuilt in the page fault handler. With this patch, the TDP MMU does not respect KVM's rate limiting on reclaim. It traverses the entire TDP structure every time. This will be addressed in a future patch. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-21-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Don't clear write flooding count for direct rootsBen Gardon
Direct roots don't have a write flooding count because the guest can't affect that paging structure. Thus there's no need to clear the write flooding count on a fast CR3 switch for direct roots. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-20-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Support MMIO in the TDP MMUBen Gardon
In order to support MMIO, KVM must be able to walk the TDP paging structures to find mappings for a given GFN. Support this walk for the TDP MMU. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 v2: Thanks to Dan Carpenter and kernel test robot for finding that root was used uninitialized in get_mmio_spte. Signed-off-by: Ben Gardon <bgardon@google.com> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Message-Id: <20201014182700.2888246-19-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Support write protection for nesting in tdp MMUBen Gardon
To support nested virtualization, KVM will sometimes need to write protect pages which are part of a shadowed paging structure or are not writable in the shadowed paging structure. Add a function to write protect GFN mappings for this purpose. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-18-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Support disabling dirty logging for the tdp MMUBen Gardon
Dirty logging ultimately breaks down MMU mappings to 4k granularity. When dirty logging is no longer needed, these granaular mappings represent a useless performance penalty. When dirty logging is disabled, search the paging structure for mappings that could be re-constituted into a large page mapping. Zap those mappings so that they can be faulted in again at a higher mapping level. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-17-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Support dirty logging for the TDP MMUBen Gardon
Dirty logging is a key feature of the KVM MMU and must be supported by the TDP MMU. Add support for both the write protection and PML dirty logging modes. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-16-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Support changed pte notifier in tdp MMUBen Gardon
In order to interoperate correctly with the rest of KVM and other Linux subsystems, the TDP MMU must correctly handle various MMU notifiers. Add a hook and handle the change_pte MMU notifier. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-15-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Add access tracking for tdp_mmuBen Gardon
In order to interoperate correctly with the rest of KVM and other Linux subsystems, the TDP MMU must correctly handle various MMU notifiers. The main Linux MM uses the access tracking MMU notifiers for swap and other features. Add hooks to handle the test/flush HVA (range) family of MMU notifiers. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-14-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Support invalidate range MMU notifier for TDP MMUBen Gardon
In order to interoperate correctly with the rest of KVM and other Linux subsystems, the TDP MMU must correctly handle various MMU notifiers. Add hooks to handle the invalidate range family of MMU notifiers. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-13-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Allocate struct kvm_mmu_pages for all pages in TDP MMUBen Gardon
Attach struct kvm_mmu_pages to every page in the TDP MMU to track metadata, facilitate NX reclaim, and enable inproved parallelism of MMU operations in future patches. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-12-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-23kvm: x86/mmu: Add TDP MMU PF handlerBen Gardon
Add functions to handle page faults in the TDP MMU. These page faults are currently handled in much the same way as the x86 shadow paging based MMU, however the ordering of some operations is slightly different. Future patches will add eager NX splitting, a fast page fault handler, and parallel page faults. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-11-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21kvm: x86/mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator argBen Gardon
In order to avoid creating executable hugepages in the TDP MMU PF handler, remove the dependency between disallowed_hugepage_adjust and the shadow_walk_iterator. This will open the function up to being used by the TDP MMU PF handler in a future patch. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-10-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21kvm: x86/mmu: Support zapping SPTEs in the TDP MMUBen Gardon
Add functions to zap SPTEs to the TDP MMU. These are needed to tear down TDP MMU roots properly and implement other MMU functions which require tearing down mappings. Future patches will add functions to populate the page tables, but as for this patch there will not be any work for these functions to do. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-8-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21kvm: x86/mmu: Add functions to handle changed TDP SPTEsBen Gardon
The existing bookkeeping done by KVM when a PTE is changed is spread around several functions. This makes it difficult to remember all the stats, bitmaps, and other subsystems that need to be updated whenever a PTE is modified. When a non-leaf PTE is marked non-present or becomes a leaf PTE, page table memory must also be freed. To simplify the MMU and facilitate the use of atomic operations on SPTEs in future patches, create functions to handle some of the bookkeeping required as a result of a change. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21kvm: x86/mmu: Allocate and free TDP MMU rootsBen Gardon
The TDP MMU must be able to allocate paging structure root pages and track the usage of those pages. Implement a similar, but separate system for root page allocation to that of the x86 shadow paging implementation. When future patches add synchronization model changes to allow for parallel page faults, these pages will need to be handled differently from the x86 shadow paging based MMU's root pages. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21kvm: x86/mmu: Init / Uninit the TDP MMUBen Gardon
The TDP MMU offers an alternative mode of operation to the x86 shadow paging based MMU, optimized for running an L1 guest with TDP. The TDP MMU will require new fields that need to be initialized and torn down. Add hooks into the existing KVM MMU initialization process to do that initialization / cleanup. Currently the initialization and cleanup fucntions do not do very much, however more operations will be added in future patches. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20201014182700.2888246-4-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21kvm: x86/mmu: Introduce tdp_iterBen Gardon
The TDP iterator implements a pre-order traversal of a TDP paging structure. This iterator will be used in future patches to create an efficient implementation of the KVM MMU for the TDP case. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21KVM: mmu: extract spte.h and spte.cPaolo Bonzini
The SPTE format will be common to both the shadow and the TDP MMU. Extract code that implements the format to a separate module, as a first step towards adding the TDP MMU and putting mmu.c on a diet. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21KVM: mmu: Separate updating a PTE from kvm_set_pte_rmappPaolo Bonzini
The TDP MMU's own function for the changed-PTE notifier will need to be update a PTE in the exact same way as the shadow MMU. Rather than re-implementing this logic, factor the SPTE creation out of kvm_set_pte_rmapp. Extracted out of a patch by Ben Gardon. <bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21kvm: x86/mmu: Separate making SPTEs from set_spteBen Gardon
Separate the functions for generating leaf page table entries from the function that inserts them into the paging structure. This refactoring will facilitate changes to the MMU sychronization model to use atomic compare / exchanges (which are not guaranteed to succeed) instead of a monolithic MMU lock. No functional change expected. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This commit introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Reviewed-by: Peter Shier <pshier@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21kvm: mmu: Separate making non-leaf sptes from link_shadow_pageBen Gardon
The TDP MMU page fault handler will need to be able to create non-leaf SPTEs to build up the paging structures. Rather than re-implementing the function, factor the SPTE creation out of link_shadow_page. Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell machine. This series introduced no new failures. This series can be viewed in Gerrit at: https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538 Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20200925212302.3979661-9-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21Merge branch 'kvm-fixes' into 'next'Paolo Bonzini
Pick up bugfixes from 5.9, otherwise various tests fail.
2020-10-21KVM: x86: Let the guest own CR4.FSGSBASELai Jiangshan
Add FSGSBASE to the set of possible guest-owned CR4 bits, i.e. let the guest own it on VMX. KVM never queries the guest's CR4.FSGSBASE value, thus there is no reason to force VM-Exit on FSGSBASE being toggled. Note, because FSGSBASE is conditionally available, this is dependent on recent changes to intercept reserved CR4 bits and to update the CR4 guest/host mask in response to guest CPUID changes. Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> [sean: added justification in changelog] Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200930041659.28181-6-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21KVM: VMX: Intercept guest reserved CR4 bits to inject #GP faultSean Christopherson
Intercept CR4 bits that are guest reserved so that KVM correctly injects a #GP fault if the guest attempts to set a reserved bit. If a feature is supported by the CPU but is not exposed to the guest, and its associated CR4 bit is not intercepted by KVM by default, then KVM will fail to inject a #GP if the guest sets the CR4 bit without triggering an exit, e.g. by toggling only the bit in question. Note, KVM doesn't give the guest direct access to any CR4 bits that are also dependent on guest CPUID. Yet. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200930041659.28181-5-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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