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2022-12-27KVM: arm64: selftests: Don't identity map the ucall MMIO holeOliver Upton1-2/+4
Currently the ucall MMIO hole is placed immediately after slot0, which is a relatively safe address in the PA space. However, it is possible that the same address has already been used for something else (like the guest program image) in the VA space. At least in my own testing, building the vgic_irq test with clang leads to the MMIO hole appearing underneath gicv3_ops. Stop identity mapping the MMIO hole and instead find an unused VA to map to it. Yet another subtle detail of the KVM selftests library is that virt_pg_map() does not update vm->vpages_mapped. Switch over to virt_map() instead to guarantee that the chosen VA isn't to something else. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Message-Id: <20221209015307.1781352-6-oliver.upton@linux.dev> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-16KVM: selftests: Add ucall pool based implementationPeter Gonda1-5/+2
To play nice with guests whose stack memory is encrypted, e.g. AMD SEV, introduce a new "ucall pool" implementation that passes the ucall struct via dedicated memory (which can be mapped shared, a.k.a. as plain text). Because not all architectures have access to the vCPU index in the guest, use a bitmap with atomic accesses to track which entries in the pool are free/used. A list+lock could also work in theory, but synchronizing the individual pointers to the guest would be a mess. Note, there's no need to rewalk the bitmap to ensure success. If all vCPUs are simply allocating, success is guaranteed because there are enough entries for all vCPUs. If one or more vCPUs are freeing and then reallocating, success is guaranteed because vCPUs _always_ walk the bitmap from 0=>N; if vCPU frees an entry and then wins a race to re-allocate, then either it will consume the entry it just freed (bit is the first free bit), or the losing vCPU is guaranteed to see the freed bit (winner consumes an earlier bit, which the loser hasn't yet visited). Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Signed-off-by: Peter Gonda <pgonda@google.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20221006003409.649993-8-seanjc@google.com
2022-11-16KVM: selftests: Drop now-unnecessary ucall_uninit()Sean Christopherson1-12/+2
Drop ucall_uninit() and ucall_arch_uninit() now that ARM doesn't modify the host's copy of ucall_exit_mmio_addr, i.e. now that there's no need to reset the pointer before potentially creating a new VM. The few calls to ucall_uninit() are all immediately followed by kvm_vm_free(), and that is likely always going to hold true, i.e. it's extremely unlikely a test will want to effectively disable ucall in the middle of a test. Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Tested-by: Peter Gonda <pgonda@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20221006003409.649993-7-seanjc@google.com
2022-11-16KVM: selftests: Make arm64's MMIO ucall multi-VM friendlySean Christopherson1-5/+14
Fix a mostly-theoretical bug where ARM's ucall MMIO setup could result in different VMs stomping on each other by cloberring the global pointer. Fix the most obvious issue by saving the MMIO gpa into the VM. A more subtle bug is that creating VMs in parallel (on multiple tasks) could result in a VM using the wrong address. Synchronizing a global to a guest effectively snapshots the value on a per-VM basis, i.e. the "global" is already prepped to work with multiple VMs, but setting the global in the host is not thread-safe. To fix that bug, add write_guest_global() to allow stuffing a VM's copy of a "global" without modifying the host value. Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Tested-by: Peter Gonda <pgonda@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20221006003409.649993-6-seanjc@google.com
2022-11-16KVM: selftests: Automatically do init_ucall() for non-barebones VMsSean Christopherson1-51/+3
Do init_ucall() automatically during VM creation to kill two (three?) birds with one stone. First, initializing ucall immediately after VM creations allows forcing aarch64's MMIO ucall address to immediately follow memslot0. This is still somewhat fragile as tests could clobber the MMIO address with a new memslot, but it's safe-ish since tests have to be conversative when accounting for memslot0. And this can be hardened in the future by creating a read-only memslot for the MMIO page (KVM ARM exits with MMIO if the guest writes to a read-only memslot). Add a TODO to document that selftests can and should use a memslot for the ucall MMIO (doing so requires yet more rework because tests assumes thay can use all memslots except memslot0). Second, initializing ucall for all VMs prepares for making ucall initialization meaningful on all architectures. aarch64 is currently the only arch that needs to do any setup, but that will change in the future by switching to a pool-based implementation (instead of the current stack-based approach). Lastly, defining the ucall MMIO address from common code will simplify switching all architectures (except s390) to a common MMIO-based ucall implementation (if there's ever sufficient motivation to do so). Cc: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Tested-by: Peter Gonda <pgonda@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20221006003409.649993-4-seanjc@google.com
2022-11-16KVM: selftests: Consolidate boilerplate code in get_ucall()Sean Christopherson1-11/+3
Consolidate the actual copying of a ucall struct from guest=>host into the common get_ucall(). Return a host virtual address instead of a guest virtual address even though the addr_gva2hva() part could be moved to get_ucall() too. Conceptually, get_ucall() is invoked from the host and should return a host virtual address (and returning NULL for "nothing to see here" is far superior to returning 0). Use pointer shenanigans instead of an unnecessary bounce buffer when the caller of get_ucall() provides a valid pointer. Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Tested-by: Peter Gonda <pgonda@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20221006003409.649993-3-seanjc@google.com
2022-11-16KVM: selftests: Consolidate common code for populating ucall structSean Christopherson1-17/+5
Make ucall() a common helper that populates struct ucall, and only calls into arch code to make the actually call out to userspace. Rename all arch-specific helpers to make it clear they're arch-specific, and to avoid collisions with common helpers (one more on its way...) Add WRITE_ONCE() to stores in ucall() code (as already done to aarch64 code in commit 9e2f6498efbb ("selftests: KVM: Handle compiler optimizations in ucall")) to prevent clang optimizations breaking ucalls. Cc: Colton Lewis <coltonlewis@google.com> Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Tested-by: Peter Gonda <pgonda@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20221006003409.649993-2-seanjc@google.com
2022-08-01Merge remote-tracking branch 'kvm/next' into kvm-next-5.20Paolo Bonzini1-7/+6
KVM/s390, KVM/x86 and common infrastructure changes for 5.20 x86: * Permit guests to ignore single-bit ECC errors * Fix races in gfn->pfn cache refresh; do not pin pages tracked by the cache * Intel IPI virtualization * Allow getting/setting pending triple fault with KVM_GET/SET_VCPU_EVENTS * PEBS virtualization * Simplify PMU emulation by just using PERF_TYPE_RAW events * More accurate event reinjection on SVM (avoid retrying instructions) * Allow getting/setting the state of the speaker port data bit * Refuse starting the kvm-intel module if VM-Entry/VM-Exit controls are inconsistent * "Notify" VM exit (detect microarchitectural hangs) for Intel * Cleanups for MCE MSR emulation s390: * add an interface to provide a hypervisor dump for secure guests * improve selftests to use TAP interface * enable interpretive execution of zPCI instructions (for PCI passthrough) * First part of deferred teardown * CPU Topology * PV attestation * Minor fixes Generic: * new selftests API using struct kvm_vcpu instead of a (vm, id) tuple x86: * Use try_cmpxchg64 instead of cmpxchg64 * Bugfixes * Ignore benign host accesses to PMU MSRs when PMU is disabled * Allow disabling KVM's "MONITOR/MWAIT are NOPs!" behavior * x86/MMU: Allow NX huge pages to be disabled on a per-vm basis * Port eager page splitting to shadow MMU as well * Enable CMCI capability by default and handle injected UCNA errors * Expose pid of vcpu threads in debugfs * x2AVIC support for AMD * cleanup PIO emulation * Fixes for LLDT/LTR emulation * Don't require refcounted "struct page" to create huge SPTEs x86 cleanups: * Use separate namespaces for guest PTEs and shadow PTEs bitmasks * PIO emulation * Reorganize rmap API, mostly around rmap destruction * Do not workaround very old KVM bugs for L0 that runs with nesting enabled * new selftests API for CPUID
2022-06-23selftests: KVM: Handle compiler optimizations in ucallRaghavendra Rao Ananta1-5/+4
The selftests, when built with newer versions of clang, is found to have over optimized guests' ucall() function, and eliminating the stores for uc.cmd (perhaps due to no immediate readers). This resulted in the userspace side always reading a value of '0', and causing multiple test failures. As a result, prevent the compiler from optimizing the stores in ucall() with WRITE_ONCE(). Suggested-by: Ricardo Koller <ricarkol@google.com> Suggested-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> Message-Id: <20220615185706.1099208-1-rananta@google.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-11KVM: selftests: Purge vm+vcpu_id == vcpu sillinessSean Christopherson1-4/+4
Take a vCPU directly instead of a VM+vcpu pair in all vCPU-scoped helpers and ioctls. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-11KVM: selftests: Get rid of kvm_util_internal.hSean Christopherson1-1/+0
Fold kvm_util_internal.h into kvm_util_base.h, i.e. make all KVM utility stuff "public". Hiding struct implementations from tests has been a massive failure, as it has led to pointless and poorly named wrappers, unnecessarily opaque code, etc... Not to mention that the approach was a complete failure as evidenced by the non-zero number of tests that were including kvm_util_internal.h. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-08selftests: kvm: replace ternary operator with min()Guo Zhengkui1-2/+2
Fix the following coccicheck warnings: tools/testing/selftests/kvm/lib/s390x/ucall.c:25:15-17: WARNING opportunity for min() tools/testing/selftests/kvm/lib/x86_64/ucall.c:27:15-17: WARNING opportunity for min() tools/testing/selftests/kvm/lib/riscv/ucall.c:56:15-17: WARNING opportunity for min() tools/testing/selftests/kvm/lib/aarch64/ucall.c:82:15-17: WARNING opportunity for min() tools/testing/selftests/kvm/lib/aarch64/ucall.c:55:20-21: WARNING opportunity for min() min() is defined in tools/include/linux/kernel.h. Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com> Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Anup Patel <anup@brainfault.org> Message-Id: <20220511120621.36956-1-guozhengkui@vivo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24KVM: selftests: Unconditionally use memslot '0' for page table allocationsSean Christopherson1-1/+1
Drop the memslot param from virt_pg_map() and virt_map() and shove the hardcoded '0' down to the vm_phy_page_alloc() calls. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210622200529.3650424-13-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-08selftests: kvm: Clear uc so UCALL_NONE is being properly reportedAaron Lewis1-0/+3
Ensure the out value 'uc' in get_ucall() is properly reporting UCALL_NONE if the call fails. The return value will be correctly reported, however, the out parameter 'uc' will not be. Clear the struct to ensure the correct value is being reported in the out parameter. Signed-off-by: Aaron Lewis <aaronlewis@google.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Alexander Graf <graf@amazon.com> Message-Id: <20201012194716.3950330-3-aaronlewis@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16selftests: kvm: Uses TEST_FAIL in tests/utilitiesWainer dos Santos Moschetta1-1/+1
Changed all tests and utilities to use TEST_FAIL macro instead of TEST_ASSERT(false,...). Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-08-02KVM: selftests: Split ucall.c into architecture specific filesThomas Huth1-0/+112
The way we exit from a guest to userspace is very specific to the architecture: On x86, we use PIO, on aarch64 we are using MMIO and on s390x we're going to use an instruction instead. The possibility to select a type via the ucall_type_t enum is currently also completely unused, so the code in ucall.c currently looks more complex than required. Let's split this up into architecture specific ucall.c files instead, so we can get rid of the #ifdefs and the unnecessary ucall_type_t handling. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Link: https://lore.kernel.org/r/20190731151525.17156-2-thuth@redhat.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>