Add an architecture specific ucall.h and inline the simple arch hooks,
e.g. the init hook for everything except ARM, and the actual "do ucall"
hook for everything except x86 (which should be simple, but temporarily
isn't due to carrying a workaround).
Having a per-arch ucall header will allow adding a #define for the
expected KVM exit reason for a ucall that is colocated (for everything
except x86) with the ucall itself.
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230731203026.1192091-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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>
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
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
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
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
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
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 9e2f6498ef ("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
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
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>
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>
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>
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>
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>
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>
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>
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>
Sean Christopherson
Oliver Upton
Peter Gonda
Paolo Bonzini
Raghavendra Rao Ananta
Guo Zhengkui
Aaron Lewis
Wainer dos Santos Moschetta
Thomas Huth