- 08 Jul, 2020 33 commits
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Sean Christopherson authored
Propagate any error returned by make_mmu_pages_available() out to userspace instead of resuming the guest if the error occurs while handling a page fault. Now that zapping the oldest MMU pages skips active roots, i.e. fails if and only if there are no zappable pages, there is no chance for a false positive, i.e. no chance of returning a spurious error to userspace. Signed-off-by:
Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200623193542.7554-5-sean.j.christopherson@intel.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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Sean Christopherson authored
Use the recently introduced kvm_mmu_zap_oldest_mmu_pages() to batch zap MMU pages when shrinking a slab. This fixes a long standing issue where KVM's shrinker implementation is completely ineffective due to zapping only a single page. E.g. without batch zapping, forcing a scan via drop_caches basically has no impact on a VM with ~2k shadow pages. With batch zapping, the number of shadow pages can be reduced to a few hundred pages in one or two runs of drop_caches. Note, if the default batch size (currently 128) is problematic, e.g. zapping 128 pages holds mmu_lock for too long, KVM can bound the batch size by setting @batch in mmu_shrinker. Signed-off-by:
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Sean Christopherson authored
Collect MMU pages for zapping in a loop when making MMU pages available, and skip over active roots when doing so as zapping an active root can never immediately free up a page. Batching the zapping avoids multiple remote TLB flushes and remedies the issue where the loop would bail early if an active root was encountered. Signed-off-by:
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Sean Christopherson authored
Delete a shadow page from the invalidation list instead of throwing it back on the list of active pages when it's a root shadow page with active users. Invalid active root pages will be explicitly freed by mmu_free_root_page() when the root_count hits zero, i.e. they don't need to be put on the active list to avoid leakage. Use sp->role.invalid to detect that a shadow page has already been zapped, i.e. is not on a list. WARN if an invalid page is encountered when zapping pages, as it should now be impossible. Signed-off-by:
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Sean Christopherson authored
Skip the unsync checks and the write flooding clearing for fully direct MMUs, which are guaranteed to not have unsync'd or indirect pages (write flooding detection only applies to indirect pages). For TDP, this avoids unnecessary memory reads and writes, and for the write flooding count will also avoid dirtying a cache line (unsync_child_bitmap itself consumes a cache line, i.e. write_flooding_count is guaranteed to be in a different cache line than parent_ptes). Signed-off-by:
Jon Cargille <jcargill@google.com> Signed-off-by:
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Sean Christopherson authored
Refactor for_each_valid_sp() to take the list of shadow pages instead of retrieving it from a gfn to avoid doing the gfn->list hash and lookup multiple times during kvm_get_mmu_page(). Cc: Peter Feiner <pfeiner@google.com> Cc: Jon Cargille <jcargill@google.com> Cc: Jim Mattson <jmattson@google.com> Signed-off-by:
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Uros Bizjak authored
Current minimum required version of binutils is 2.23, which supports VMCALL and VMMCALL instruction mnemonics. Replace the byte-wise specification of VMCALL and VMMCALL with these proper mnemonics. Signed-off-by:
Uros Bizjak <ubizjak@gmail.com> CC: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200623183439.5526-1-ubizjak@gmail.com> Signed-off-by:
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Joerg Roedel authored
Match the naming with other nested svm functions. No functional changes. Signed-off-by:
Joerg Roedel <jroedel@suse.de> Message-Id: <20200625080325.28439-5-joro@8bytes.org> Signed-off-by:
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Joerg Roedel authored
Make clear the symbols belong to the SVM code when they are built-in. No functional changes. Signed-off-by:
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Joerg Roedel authored
Make it more clear what data structure these functions operate on. No functional changes. Signed-off-by:
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Joerg Roedel authored
Renaming is only needed in the svm.h header file. No functional changes. Signed-off-by:
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Sean Christopherson authored
Add nested_vmx_fail() to wrap VM-Fail paths that _may_ result in VM-Fail Valid to make it clear at the call sites that the Valid flavor isn't guaranteed. Suggested-by:
Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by:
Jim Mattson <jmattson@google.com> Signed-off-by:
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Jim Mattson authored
Since this field is now in kvm_vcpu_arch, clean things up a little by setting it in vendor-agnostic code: vcpu_enter_guest. Note that it must be set after the call to kvm_x86_ops.run(), since it can't be updated before pre_sev_run(). Suggested-by:
Oliver Upton <oupton@google.com> Reviewed-by:
Peter Shier <pshier@google.com> Message-Id: <20200603235623.245638-7-jmattson@google.com> Signed-off-by:
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Jim Mattson authored
Both the vcpu_vmx structure and the vcpu_svm structure have a 'last_cpu' field. Move the common field into the kvm_vcpu_arch structure. For clarity, rename it to 'last_vmentry_cpu.' Suggested-by:
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Jim Mattson authored
More often than not, a failed VM-entry in an x86 production environment is induced by a defective CPU. To help identify the bad hardware, include the id of the last logical CPU to run a vCPU in the information provided to userspace on a KVM exit for failed VM-entry or for KVM internal errors not associated with emulation. The presence of this additional information is indicated by a new capability, KVM_CAP_LAST_CPU. Signed-off-by:
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Jim Mattson authored
As we already do in svm, record the last logical processor on which a vCPU has run, so that it can be communicated to userspace for potential hardware errors. Signed-off-by:
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Jim Mattson authored
Previously, this field was only set when using SEV. Set it for all vCPU configurations, so that it can be communicated to userspace for diagnosing potential hardware errors. Signed-off-by:
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Jim Mattson authored
The current logical processor id is cached in vcpu->cpu. Use it instead of raw_smp_processor_id() when a kvm_vcpu struct is available. Signed-off-by:
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Paolo Bonzini authored
Callers of sev_pin_memory() treat NULL differently: sev_launch_secret()/svm_register_enc_region() return -ENOMEM sev_dbg_crypt() returns -EFAULT. Switching to ERR_PTR() preserves the error and enables cleaner reporting of different kinds of failures. Suggested-by:
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John Hubbard authored
This code was using get_user_pages*(), in a "Case 2" scenario (DMA/RDMA), using the categorization from [1]. That means that it's time to convert the get_user_pages*() + put_page() calls to pin_user_pages*() + unpin_user_pages() calls. There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wanpeng Li <wanpengli@tencent.com> Cc: Jim Mattson <jmattson@google.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: x86@kernel.org Cc: kvm@vger.kernel.org Signed-off-by:John Hubbard <jhubbard@nvidia.com> Message-Id: <20200526062207.1360225-3-jhubbard@nvidia.com> Signed-off-by:
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John Hubbard authored
There are two problems in svn_pin_memory(): 1) The return value of get_user_pages_fast() is stored in an unsigned long, although the declared return value is of type int. This will not cause any symptoms, but it is misleading. Fix this by changing the type of npinned to "int". 2) The number of pages passed into get_user_pages_fast() is stored in an unsigned long, even though get_user_pages_fast() accepts an int. This means that it is possible to silently overflow the number of pages. Fix this by adding a WARN_ON_ONCE() and an early error return. The npages variable is left as an unsigned long for convenience in checking for overflow. Fixes: 89c50580 ("KVM: SVM: Add support for KVM_SEV_LAUNCH_UPDATE_DATA command") Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wanpeng Li <wanpengli@tencent.com> Cc: Jim Mattson <jmattson@google.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: x86@kernel.org Cc: kvm@vger.kernel.org Signed-off-by:
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Krish Sadhukhan authored
According to section "Canonicalization and Consistency Checks" in APM vol. 2 the following guest state is illegal: "DR6[63:32] are not zero." "DR7[63:32] are not zero." "Any MBZ bit of EFER is set." Signed-off-by:Krish Sadhukhan <krish.sadhukhan@oracle.com> Message-Id: <20200522221954.32131-3-krish.sadhukhan@oracle.com> Signed-off-by:
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Krish Sadhukhan authored
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Peter Xu authored
Logically the ignore_msrs and report_ignored_msrs should also apply to feature MSRs. Add them in. Signed-off-by:
Peter Xu <peterx@redhat.com> Message-Id: <20200622220442.21998-3-peterx@redhat.com> Signed-off-by:
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Peter Xu authored
MSR accesses can be one of: (1) KVM internal access, (2) userspace access (e.g., via KVM_SET_MSRS ioctl), (3) guest access. The ignore_msrs was previously handled by kvm_get_msr_common() and kvm_set_msr_common(), which is the bottom of the msr access stack. It's working in most cases, however it could dump unwanted warning messages to dmesg even if kvm get/set the msrs internally when calling __kvm_set_msr() or __kvm_get_msr() (e.g. kvm_cpuid()). Ideally we only want to trap cases (2) or (3), but not (1) above. To achieve this, move the ignore_msrs handling upper until the callers of __kvm_get_msr() and __kvm_set_msr(). To identify the "msr missing" event, a new return value (KVM_MSR_RET_INVALID==2) is used for that. Signed-off-by:
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Sean Christopherson authored
Move .write_log_dirty() into kvm_x86_nested_ops to help differentiate it from the non-nested dirty log hooks. And because it's a nested-only operation. Signed-off-by:
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Sean Christopherson authored
WARN if vmx_write_pml_buffer() is called outside of guest mode instead of silently ignoring the condition. The only caller is nested EPT's ept_update_accessed_dirty_bits(), which should only be reachable when L2 is active. Signed-off-by:
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Sean Christopherson authored
Drop kvm_arch_write_log_dirty() in favor of invoking .write_log_dirty() directly from FNAME(update_accessed_dirty_bits). "kvm_arch" is usually used for x86 functions that are invoked from generic KVM, and implies that there are external callers, neither of which is true. Remove the check for a non-NULL kvm_x86_ops hook as the call is wrapped in PTTYPE_EPT and is unconditionally set by VMX. Signed-off-by:
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Vitaly Kuznetsov authored
Unlike normal 'int' functions returning '0' on success, kvm_setup_async_pf()/ kvm_arch_setup_async_pf() return '1' when a job to handle page fault asynchronously was scheduled and '0' otherwise. To avoid the confusion change return type to 'bool'. No functional change intended. Suggested-by:
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Vitaly Kuznetsov authored
KVM guest code in Linux enables APF only when KVM_FEATURE_ASYNC_PF_INT is supported, this means we will never see KVM_PV_REASON_PAGE_READY when handling page fault vmexit in KVM. While on it, make sure we only follow genuine page fault path when APF reason is zero. If we happen to see something else this means that the underlying hypervisor is misbehaving. Leave WARN_ON_ONCE() to catch that. Signed-off-by:
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Paolo Bonzini authored
Merge 5.8-rc bugfixes.
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Paolo Bonzini authored
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Colin Ian King authored
There is a spelling mistake in a couple of kvm_err messages. Fix them. Signed-off-by:
Colin Ian King <colin.king@canonical.com> Message-Id: <20200615082636.7004-1-colin.king@canonical.com> Signed-off-by:
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- 06 Jul, 2020 3 commits
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Paolo Bonzini authored
Merge tag 'kvmarm-fixes-5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master KVM/arm fixes for 5.8, take #3 - Disable preemption on context-switching PMU EL0 state happening on system register trap - Don't clobber X0 when tearing down KVM via a soft reset (kexec)
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Andrew Scull authored
HVC_SOFT_RESTART is given values for x0-2 that it should installed before exiting to the new address so should not set x0 to stub HVC success or failure code. Fixes: af42f204 ("arm64: hyp-stub: Zero x0 on successful stub handling") Cc: stable@vger.kernel.org Signed-off-by:
Andrew Scull <ascull@google.com> Signed-off-by:
Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200706095259.1338221-1-ascull@google.com
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Marc Zyngier authored
Commit 07da1ffa ("KVM: arm64: Remove host_cpu_context member from vcpu structure") has, by removing the host CPU context pointer, exposed that kvm_vcpu_pmu_restore_guest is called in preemptible contexts: [ 266.932442] BUG: using smp_processor_id() in preemptible [00000000] code: qemu-system-aar/779 [ 266.939721] caller is debug_smp_processor_id+0x20/0x30 [ 266.944157] CPU: 2 PID: 779 Comm: qemu-system-aar Tainted: G E 5.8.0-rc3-00015-g8d4aa58b2fe3 #1374 [ 266.954268] Hardware name: amlogic w400/w400, BIOS 2020.04 05/22/2020 [ 266.960640] Call trace: [ 266.963064] dump_backtrace+0x0/0x1e0 [ 266.966679] show_stack+0x20/0x30 [ 266.969959] dump_stack+0xe4/0x154 [ 266.973338] check_preemption_disabled+0xf8/0x108 [ 266.977978] debug_smp_processor_id+0x20/0x30 [ 266.982307] kvm_vcpu_pmu_restore_guest+0x2c/0x68 [ 266.986949] access_pmcr+0xf8/0x128 [ 266.990399] perform_access+0x8c/0x250 [ 266.994108] kvm_handle_sys_reg+0x10c/0x2f8 [ 266.998247] handle_exit+0x78/0x200 [ 267.001697] kvm_arch_vcpu_ioctl_run+0x2ac/0xab8 Note that the bug was always there, it is only the switch to using percpu accessors that made it obvious. The fix is to wrap these accesses in a preempt-disabled section, so that we sample a coherent context on trap from the guest. Fixes: 435e53fb ("arm64: KVM: Enable VHE support for :G/:H perf event modifiers") Cc:: Andrew Murray <amurray@thegoodpenguin.co.uk> Signed-off-by:
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- 03 Jul, 2020 3 commits
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Sean Christopherson authored
Use the "common" KVM_POSSIBLE_CR*_GUEST_BITS defines to initialize the CR0/CR4 guest host masks instead of duplicating most of the CR4 mask and open coding the CR0 mask. SVM doesn't utilize the masks, i.e. the masks are effectively VMX specific even if they're not named as such. This avoids duplicate code, better documents the guest owned CR0 bit, and eliminates the need for a build-time assertion to keep VMX and x86 synchronized. Signed-off-by:
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Sean Christopherson authored
Mark CR4.TSD as being possibly owned by the guest as that is indeed the case on VMX. Without TSD being tagged as possibly owned by the guest, a targeted read of CR4 to get TSD could observe a stale value. This bug is benign in the current code base as the sole consumer of TSD is the emulator (for RDTSC) and the emulator always "reads" the entirety of CR4 when grabbing bits. Add a build-time assertion in to ensure VMX doesn't hand over more CR4 bits without also updating x86. Fixes: 52ce3c21 ("x86,kvm,vmx: Don't trap writes to CR4.TSD") Cc: stable@vger.kernel.org Signed-off-by:
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Sean Christopherson authored
Inject a #GP on MOV CR4 if CR4.LA57 is toggled in 64-bit mode, which is illegal per Intel's SDM: CR4.LA57 57-bit linear addresses (bit 12 of CR4) ... blah blah blah ... This bit cannot be modified in IA-32e mode. Note, the pseudocode for MOV CR doesn't call out the fault condition, which is likely why the check was missed during initial development. This is arguably an SDM bug and will hopefully be fixed in future release of the SDM. Fixes: fd8cb433 ("KVM: MMU: Expose the LA57 feature to VM.") Cc: stable@vger.kernel.org Reported-by:Sebastien Boeuf <sebastien.boeuf@intel.com> Signed-off-by:
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- 02 Jul, 2020 1 commit
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Paolo Bonzini authored
Sparse complains on a call to get_compat_sigset, fix it. The "if" right above explains that sigmask_arg->sigset is basically a compat_sigset_t. Signed-off-by:
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