- 22 Feb, 2021 1 commit
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Paolo Bonzini authored
Right now, enter_svm_guest_mode is calling nested_prepare_vmcb_save and nested_prepare_vmcb_control. This results in is_guest_mode being false until the end of nested_prepare_vmcb_control. This is a problem because nested_prepare_vmcb_save can in turn cause changes to the intercepts and these have to be applied to the "host VMCB" (stored in svm->nested.hsave) and then merged with the VMCB12 intercepts into svm->vmcb. In particular, without this change we forget to set the CR0 read and CR0 write intercepts when running a real mode L2 guest with NPT disabled. The guest is therefore able to see the CR0.PG bit that KVM sets to enable "paged real mode". This patch fixes the svm.flat mode_switch test case with npt=0. There are no other problematic calls in nested_prepare_vmcb_save. Moving is_guest_mode to the end is done since commit 06fc7772 ("KVM: SVM: Activate nested state only when guest state is complete", 2010-04-25). However, back then KVM didn't grab a different VMCB when updating the intercepts, it had already copied/merged L1's stuff to L0's VMCB, and then updated L0's VMCB regardless of is_nested(). Later recalc_intercepts was introduced in commit 384c6368 ("KVM: SVM: Add function to recalculate intercept masks", 2011-01-12). This introduced the bug, because recalc_intercepts now throws away the intercept manipulations that svm_set_cr0 had done in the meanwhile to svm->vmcb. [1] https://lore.kernel.org/kvm/1266493115-28386-1-git-send-email-joerg.roedel@amd.com/Reviewed-by:
Sean Christopherson <seanjc@google.com> Tested-by:
Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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- 19 Feb, 2021 13 commits
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Sean Christopherson authored
Remove several exports from the MMU that are no longer necessary. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Drop kvm_mmu_slot_largepage_remove_write_access() and refactor its sole caller to use kvm_mmu_slot_remove_write_access(). Remove the now-unused slot_handle_large_level() and slot_handle_all_level() helpers. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Stop setting dirty bits for MMU pages when dirty logging is disabled for a memslot, as PML is now completely disabled when there are no memslots with dirty logging enabled. This means that spurious PML entries will be created for memslots with dirty logging disabled if at least one other memslot has dirty logging enabled. However, spurious PML entries are already possible since dirty bits are set only when a dirty logging is turned off, i.e. memslots that are never dirty logged will have dirty bits cleared. In the end, it's faster overall to eat a few spurious PML entries in the window where dirty logging is being disabled across all memslots. Signed-off-by:
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Makarand Sonare authored
Currently, if enable_pml=1 PML remains enabled for the entire lifetime of the VM irrespective of whether dirty logging is enable or disabled. When dirty logging is disabled, all the pages of the VM are manually marked dirty, so that PML is effectively non-operational. Setting the dirty bits is an expensive operation which can cause severe MMU lock contention in a performance sensitive path when dirty logging is disabled after a failed or canceled live migration. Manually setting dirty bits also fails to prevent PML activity if some code path clears dirty bits, which can incur unnecessary VM-Exits. In order to avoid this extra overhead, dynamically enable/disable PML when dirty logging gets turned on/off for the first/last memslot. Signed-off-by:
Makarand Sonare <makarandsonare@google.com> Co-developed-by:
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Sean Christopherson authored
Add a sanity check in kvm_mmu_slot_apply_flags to assert that the LOG_DIRTY_PAGES flag is indeed being toggled, and explicitly rely on that holding true when zapping collapsible SPTEs. Manipulating the CPU dirty log (PML) and write-protection also relies on this assertion, but that's not obvious in the current code. Signed-off-by:
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Sean Christopherson authored
Drop the facade of KVM's PML logic being vendor specific and move the bits that aren't truly VMX specific into common x86 code. The MMU logic for dealing with PML is tightly coupled to the feature and to VMX's implementation, bouncing through kvm_x86_ops obfuscates the code without providing any meaningful separation of concerns or encapsulation. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Store the vendor-specific dirty log size in a variable, there's no need to wrap it in a function since the value is constant after hardware_setup() runs. Signed-off-by:
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Sean Christopherson authored
Expand the comment about need to use write-protection for nested EPT when PML is enabled to clarify that the tagging is a nop when PML is _not_ enabled. Without the clarification, omitting the PML check looks wrong at first^Wfifth glance. Signed-off-by:
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Sean Christopherson authored
Unconditionally disable PML in vmcs02, KVM emulates PML purely in the MMU, e.g. vmx_flush_pml_buffer() doesn't even try to copy the L2 GPAs from vmcs02's buffer to vmcs12. At best, enabling PML is a nop. At worst, it will cause vmx_flush_pml_buffer() to record bogus GFNs in the dirty logs. Initialize vmcs02.GUEST_PML_INDEX such that PML writes would trigger VM-Exit if PML was somehow enabled, skip flushing the buffer for guest mode since the index is bogus, and freak out if a PML full exit occurs when L2 is active. Signed-off-by:
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Sean Christopherson authored
When zapping SPTEs in order to rebuild them as huge pages, use the new helper that computes the max mapping level to detect whether or not a SPTE should be zapped. Doing so avoids zapping SPTEs that can't possibly be rebuilt as huge pages, e.g. due to hardware constraints, memslot alignment, etc... This also avoids zapping SPTEs that are still large, e.g. if migration was canceled before write-protected huge pages were shattered to enable dirty logging. Note, such pages are still write-protected at this time, i.e. a page fault VM-Exit will still occur. This will hopefully be addressed in a future patch. Sadly, TDP MMU loses its const on the memslot, but that's a pervasive problem that's been around for quite some time. Signed-off-by:
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Sean Christopherson authored
Pass the memslot to the rmap callbacks, it will be used when zapping collapsible SPTEs to verify the memslot is compatible with hugepages before zapping its SPTEs. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Factor out the logic for determining the maximum mapping level given a memslot and a gpa. The helper will be used when zapping collapsible SPTEs when disabling dirty logging, e.g. to avoid zapping SPTEs that can't possibly be rebuilt as hugepages. No functional change intended. Signed-off-by:
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Sean Christopherson authored
Zap SPTEs that are backed by ZONE_DEVICE pages when zappings SPTEs to rebuild them as huge pages in the TDP MMU. ZONE_DEVICE huge pages are managed differently than "regular" pages and are not compound pages. Likewise, PageTransCompoundMap() will not detect HugeTLB, so switch to PageCompound(). This matches the similar check in kvm_mmu_zap_collapsible_spte. Cc: Ben Gardon <bgardon@google.com> Fixes: 14881998 ("kvm: x86/mmu: Support disabling dirty logging for the tdp MMU") Signed-off-by:
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- 18 Feb, 2021 7 commits
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Paolo Bonzini authored
This is not needed because the tweak was done on the guest_mmu, while nested_ept_uninit_mmu_context has just changed vcpu->arch.walk_mmu back to the root_mmu. Suggested-by:
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Paolo Bonzini authored
In case of npt=0 on host, nSVM needs the same .inject_page_fault tweak as VMX has, to make sure that shadow mmu faults are injected as vmexits. It is not clear why this is needed at all, but for now keep the same code as VMX and we'll fix it for both. Based on a patch by Maxim Levitsky <mlevitsk@redhat.com>. Fixes: 7c86663b ("KVM: nSVM: inject exceptions via svm_check_nested_events") Cc: stable@vger.kernel.org Signed-off-by:
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Maxim Levitsky authored
This way trace will capture all the nested mode entries (including entries after migration, and from smm) Signed-off-by:
Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210217145718.1217358-3-mlevitsk@redhat.com> Signed-off-by:
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Maxim Levitsky authored
trace_kvm_exit prints this value (using vmx_get_exit_info) so it makes sense to read it before the trace point. Fixes: dcf068da ("KVM: VMX: Introduce generic fastpath handler") Signed-off-by:
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Sean Christopherson authored
Remove the restriction that prevents VMX from exposing INVPCID to the guest without PCID also being exposed to the guest. The justification of the restriction is that INVPCID will #UD if it's disabled in the VMCS. While that is a true statement, it's also true that RDTSCP will #UD if it's disabled in the VMCS. Neither of those things has any dependency whatsoever on the guest being able to set CR4.PCIDE=1, which is what is effectively allowed by exposing PCID to the guest. Removing the bogus restriction aligns VMX with SVM, and also allows for an interesting configuration. INVPCID is that fastest way to do a global TLB flush, e.g. see native_flush_tlb_global(). Allowing INVPCID without PCID would let a guest use the expedited flush while also limiting the number of ASIDs consumed by the guest. Signed-off-by:
Jim Mattson <jmattson@google.com> Signed-off-by:
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Sean Christopherson authored
Advertise INVPCID by default (if supported by the host kernel) instead of having both SVM and VMX opt in. INVPCID was opt in when it was a VMX only feature so that KVM wouldn't prematurely advertise support if/when it showed up in the kernel on AMD hardware. Signed-off-by:
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Sean Christopherson authored
Intercept INVPCID if it's disabled in the guest, even when using NPT, as KVM needs to inject #UD in this case. Fixes: 4407a797 ("KVM: SVM: Enable INVPCID feature on AMD") Cc: Babu Moger <babu.moger@amd.com> Signed-off-by:
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- 15 Feb, 2021 2 commits
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Paolo Bonzini authored
The variable in practice will never be uninitialized, because the loop will always go through at least one iteration. In case it would not, make vcpu_get_cpuid report an assertion failure. Signed-off-by: -
Ignacio Alvarado authored
This test launches 512 VMs in serial and kills them after a random amount of time. The test was original written to exercise KVM user notifiers in the context of1650b4ebc99d: - KVM: Disable irq while unregistering user notifier - https://lore.kernel.org/kvm/CACXrx53vkO=HKfwWwk+fVpvxcNjPrYmtDZ10qWxFvVX_PTGp3g@mail.gmail.com/ Recently, this test piqued my interest because it proved useful to for AMD SNP in exercising the "in-use" pages, described in APM section 15.36.12, "Running SNP-Active Virtual Machines". Signed-off-by:
Ignacio Alvarado <ikalvarado@google.com> Signed-off-by:
Marc Orr <marcorr@google.com> Message-Id: <20210213001452.1719001-1-marcorr@google.com> Signed-off-by:
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- 12 Feb, 2021 7 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarmPaolo Bonzini authored
KVM/arm64 updates for Linux 5.12 - Make the nVHE EL2 object relocatable, resulting in much more maintainable code - Handle concurrent translation faults hitting the same page in a more elegant way - Support for the standard TRNG hypervisor call - A bunch of small PMU/Debug fixes - Allow the disabling of symbol export from assembly code - Simplification of the early init hypercall handling
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Marc Zyngier authored
Signed-off-by:Marc Zyngier <maz@kernel.org>
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Marc Zyngier authored
Signed-off-by: -
Marc Zyngier authored
Signed-off-by: -
Marc Zyngier authored
Signed-off-by: -
Marc Zyngier authored
Signed-off-by: -
Marc Zyngier authored
KVM/arm64 fixes for 5.11, take #2 - Don't allow tagged pointers to point to memslots - Filter out ARMv8.1+ PMU events on v8.0 hardware - Hide PMU registers from userspace when no PMU is configured - More PMU cleanups - Don't try to handle broken PSCI firmware - More sys_reg() to reg_to_encoding() conversions Signed-off-by:
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- 11 Feb, 2021 10 commits
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Sean Christopherson authored
Add a 2 byte pad to struct compat_vcpu_info so that the sum size of its fields is actually 64 bytes. The effective size without the padding is also 64 bytes due to the compiler aligning evtchn_pending_sel to a 4-byte boundary, but depending on compiler alignment is subtle and unnecessary. Opportunistically replace spaces with tables in the other fields. Cc: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by:
David Woodhouse <dwmw@amazon.co.uk> Signed-off-by:
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Sean Christopherson authored
Don't bother mapping the Xen shinfo pages into the guest, they don't need to be accessed using the GVAs and passing a define with "GPA" in the name to addr_gva2hpa() is confusing. Cc: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by:
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Sean Christopherson authored
The Xen shinfo selftest uses '40' when setting the GPA of the vCPU info struct, but checks for the result at '0x40'. Arbitrarily use the hex version to resolve the bug. Fixes: 8d4e7e80 ("KVM: x86: declare Xen HVM shared info capability and add test case") Cc: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by:
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Sean Christopherson authored
For better or worse, the memslot APIs take the number of pages, not the size in bytes. The Xen tests need 2 pages, not 8192 pages. Fixes: 8d4e7e80 ("KVM: x86: declare Xen HVM shared info capability and add test case") Cc: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by:
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Sean Christopherson authored
Add the new Xen test binaries to KVM selftest's .gitnore. Signed-off-by:
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Peter Shier authored
Fixes: 678e90a3 ("KVM: selftests: Test IPI to halted vCPU in xAPIC while backing page moves") Cc: Andrew Jones <drjones@redhat.com> Cc: Jim Mattson <jmattson@google.com> Signed-off-by:
Peter Shier <pshier@google.com> Signed-off-by:
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Ricardo Koller authored
Building the KVM selftests with LLVM's integrated assembler fails with: $ CFLAGS=-fintegrated-as make -C tools/testing/selftests/kvm CC=clang lib/x86_64/svm.c:77:16: error: too few operands for instruction asm volatile ("vmsave\n\t" : : "a" (vmcb_gpa) : "memory"); ^ <inline asm>:1:2: note: instantiated into assembly here vmsave ^ lib/x86_64/svm.c:134:3: error: too few operands for instruction "vmload\n\t" ^ <inline asm>:1:2: note: instantiated into assembly here vmload ^ This is because LLVM IAS does not currently support calling vmsave, vmload, or vmload without an explicit %rax operand. Add an explicit operand to vmsave, vmload, and vmrum in svm.c. Fixing this was suggested by Sean Christopherson. Tested: building without this error in clang 11. The following patch (not queued yet) needs to be applied to solve the other remaining error: "selftests: kvm: remove reassignment of non-absolute variables". Suggested-by:Ricardo Koller <ricarkol@google.com> Message-Id: <20210210031719.769837-1-ricarkol@google.com> Signed-off-by:
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Wei Yongjun authored
The sparse tool complains as follows: arch/x86/kvm/svm/svm.c:204:6: warning: symbol 'svm_gp_erratum_intercept' was not declared. Should it be static? This symbol is not used outside of svm.c, so this commit marks it static. Fixes: 82a11e9c ("KVM: SVM: Add emulation support for #GP triggered by SVM instructions") Reported-by:
Hulk Robot <hulkci@huawei.com> Signed-off-by:
Wei Yongjun <weiyongjun1@huawei.com> Message-Id: <20210210075958.1096317-1-weiyongjun1@huawei.com> Signed-off-by:
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Paolo Bonzini authored
Merge tag 'kvm-ppc-next-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD PPC KVM update for 5.12 - Support for second data watchpoint on POWER10, from Ravi Bangoria - Remove some complex workarounds for buggy early versions of POWER9 - Guest entry/exit fixes from Nick Piggin and Fabiano Rosas
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Waiman Long authored
include/asm-generic/qrwlock.h was trying to get arch_spin_is_locked via asm-generic/qspinlock.h. However, this does not work because architectures might be using queued rwlocks but not queued spinlocks (csky), or because they might be defining their own queued_* macros before including asm/qspinlock.h. To fix this, ensure that asm/spinlock.h always includes qrwlock.h after defining arch_spin_is_locked (either directly for csky, or via asm/qspinlock.h for other architectures). The only inclusion elsewhere is in kernel/locking/qrwlock.c. That one is really unnecessary because the file is only compiled in SMP configurations (config QUEUED_RWLOCKS depends on SMP) and in that case linux/spinlock.h already includes asm/qrwlock.h if needed, via asm/spinlock.h. Reported-by:
Guenter Roeck <linux@roeck-us.net> Signed-off-by:
Waiman Long <longman@redhat.com> Fixes: 26128cb6 ("locking/rwlocks: Add contention detection for rwlocks") Tested-by:
Ben Gardon <bgardon@google.com> [Add arch/sparc and kernel/locking parts per discussion with Waiman. - Paolo] Signed-off-by:
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