237 lines
7.2 KiB
C
237 lines
7.2 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/ioctl.h>
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#include <linux/sizes.h>
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#include <kvm_util.h>
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#include <processor.h>
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#include "ucall_common.h"
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struct kvm_coalesced_io {
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struct kvm_coalesced_mmio_ring *ring;
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uint32_t ring_size;
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uint64_t mmio_gpa;
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uint64_t *mmio;
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/*
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* x86-only, but define pio_port for all architectures to minimize the
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* amount of #ifdeffery and complexity, without having to sacrifice
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* verbose error messages.
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*/
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uint8_t pio_port;
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};
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static struct kvm_coalesced_io kvm_builtin_io_ring;
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#ifdef __x86_64__
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static const int has_pio = 1;
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#else
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static const int has_pio = 0;
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#endif
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static void guest_code(struct kvm_coalesced_io *io)
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{
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int i, j;
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for (;;) {
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for (j = 0; j < 1 + has_pio; j++) {
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/*
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* KVM always leaves one free entry, i.e. exits to
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* userspace before the last entry is filled.
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*/
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for (i = 0; i < io->ring_size - 1; i++) {
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#ifdef __x86_64__
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if (i & 1)
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outl(io->pio_port, io->pio_port + i);
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else
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#endif
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WRITE_ONCE(*io->mmio, io->mmio_gpa + i);
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}
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#ifdef __x86_64__
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if (j & 1)
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outl(io->pio_port, io->pio_port + i);
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else
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#endif
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WRITE_ONCE(*io->mmio, io->mmio_gpa + i);
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}
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GUEST_SYNC(0);
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WRITE_ONCE(*io->mmio, io->mmio_gpa + i);
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#ifdef __x86_64__
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outl(io->pio_port, io->pio_port + i);
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#endif
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}
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}
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static void vcpu_run_and_verify_io_exit(struct kvm_vcpu *vcpu,
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struct kvm_coalesced_io *io,
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uint32_t ring_start,
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uint32_t expected_exit)
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{
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const bool want_pio = expected_exit == KVM_EXIT_IO;
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struct kvm_coalesced_mmio_ring *ring = io->ring;
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struct kvm_run *run = vcpu->run;
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uint32_t pio_value;
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WRITE_ONCE(ring->first, ring_start);
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WRITE_ONCE(ring->last, ring_start);
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vcpu_run(vcpu);
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/*
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* Annoyingly, reading PIO data is safe only for PIO exits, otherwise
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* data_offset is garbage, e.g. an MMIO gpa.
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*/
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if (run->exit_reason == KVM_EXIT_IO)
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pio_value = *(uint32_t *)((void *)run + run->io.data_offset);
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else
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pio_value = 0;
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TEST_ASSERT((!want_pio && (run->exit_reason == KVM_EXIT_MMIO && run->mmio.is_write &&
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run->mmio.phys_addr == io->mmio_gpa && run->mmio.len == 8 &&
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*(uint64_t *)run->mmio.data == io->mmio_gpa + io->ring_size - 1)) ||
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(want_pio && (run->exit_reason == KVM_EXIT_IO && run->io.port == io->pio_port &&
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run->io.direction == KVM_EXIT_IO_OUT && run->io.count == 1 &&
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pio_value == io->pio_port + io->ring_size - 1)),
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"For start = %u, expected exit on %u-byte %s write 0x%llx = %lx, got exit_reason = %u (%s)\n "
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"(MMIO addr = 0x%llx, write = %u, len = %u, data = %lx)\n "
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"(PIO port = 0x%x, write = %u, len = %u, count = %u, data = %x",
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ring_start, want_pio ? 4 : 8, want_pio ? "PIO" : "MMIO",
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want_pio ? (unsigned long long)io->pio_port : io->mmio_gpa,
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(want_pio ? io->pio_port : io->mmio_gpa) + io->ring_size - 1, run->exit_reason,
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run->exit_reason == KVM_EXIT_MMIO ? "MMIO" : run->exit_reason == KVM_EXIT_IO ? "PIO" : "other",
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run->mmio.phys_addr, run->mmio.is_write, run->mmio.len, *(uint64_t *)run->mmio.data,
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run->io.port, run->io.direction, run->io.size, run->io.count, pio_value);
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}
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static void vcpu_run_and_verify_coalesced_io(struct kvm_vcpu *vcpu,
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struct kvm_coalesced_io *io,
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uint32_t ring_start,
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uint32_t expected_exit)
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{
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struct kvm_coalesced_mmio_ring *ring = io->ring;
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int i;
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vcpu_run_and_verify_io_exit(vcpu, io, ring_start, expected_exit);
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TEST_ASSERT((ring->last + 1) % io->ring_size == ring->first,
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"Expected ring to be full (minus 1), first = %u, last = %u, max = %u, start = %u",
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ring->first, ring->last, io->ring_size, ring_start);
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for (i = 0; i < io->ring_size - 1; i++) {
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uint32_t idx = (ring->first + i) % io->ring_size;
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struct kvm_coalesced_mmio *entry = &ring->coalesced_mmio[idx];
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#ifdef __x86_64__
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if (i & 1)
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TEST_ASSERT(entry->phys_addr == io->pio_port &&
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entry->len == 4 && entry->pio &&
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*(uint32_t *)entry->data == io->pio_port + i,
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"Wanted 4-byte port I/O 0x%x = 0x%x in entry %u, got %u-byte %s 0x%llx = 0x%x",
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io->pio_port, io->pio_port + i, i,
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entry->len, entry->pio ? "PIO" : "MMIO",
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entry->phys_addr, *(uint32_t *)entry->data);
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else
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#endif
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TEST_ASSERT(entry->phys_addr == io->mmio_gpa &&
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entry->len == 8 && !entry->pio,
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"Wanted 8-byte MMIO to 0x%lx = %lx in entry %u, got %u-byte %s 0x%llx = 0x%lx",
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io->mmio_gpa, io->mmio_gpa + i, i,
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entry->len, entry->pio ? "PIO" : "MMIO",
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entry->phys_addr, *(uint64_t *)entry->data);
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}
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}
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static void test_coalesced_io(struct kvm_vcpu *vcpu,
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struct kvm_coalesced_io *io, uint32_t ring_start)
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{
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struct kvm_coalesced_mmio_ring *ring = io->ring;
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kvm_vm_register_coalesced_io(vcpu->vm, io->mmio_gpa, 8, false /* pio */);
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#ifdef __x86_64__
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kvm_vm_register_coalesced_io(vcpu->vm, io->pio_port, 8, true /* pio */);
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#endif
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vcpu_run_and_verify_coalesced_io(vcpu, io, ring_start, KVM_EXIT_MMIO);
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#ifdef __x86_64__
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vcpu_run_and_verify_coalesced_io(vcpu, io, ring_start, KVM_EXIT_IO);
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#endif
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/*
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* Verify ucall, which may use non-coalesced MMIO or PIO, generates an
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* immediate exit.
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*/
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WRITE_ONCE(ring->first, ring_start);
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WRITE_ONCE(ring->last, ring_start);
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vcpu_run(vcpu);
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TEST_ASSERT_EQ(get_ucall(vcpu, NULL), UCALL_SYNC);
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TEST_ASSERT_EQ(ring->first, ring_start);
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TEST_ASSERT_EQ(ring->last, ring_start);
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/* Verify that non-coalesced MMIO/PIO generates an exit to userspace. */
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kvm_vm_unregister_coalesced_io(vcpu->vm, io->mmio_gpa, 8, false /* pio */);
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vcpu_run_and_verify_io_exit(vcpu, io, ring_start, KVM_EXIT_MMIO);
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#ifdef __x86_64__
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kvm_vm_unregister_coalesced_io(vcpu->vm, io->pio_port, 8, true /* pio */);
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vcpu_run_and_verify_io_exit(vcpu, io, ring_start, KVM_EXIT_IO);
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#endif
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}
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int main(int argc, char *argv[])
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{
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struct kvm_vcpu *vcpu;
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struct kvm_vm *vm;
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int i;
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TEST_REQUIRE(kvm_has_cap(KVM_CAP_COALESCED_MMIO));
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#ifdef __x86_64__
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TEST_REQUIRE(kvm_has_cap(KVM_CAP_COALESCED_PIO));
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#endif
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vm = vm_create_with_one_vcpu(&vcpu, guest_code);
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kvm_builtin_io_ring = (struct kvm_coalesced_io) {
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/*
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* The I/O ring is a kernel-allocated page whose address is
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* relative to each vCPU's run page, with the page offset
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* provided by KVM in the return of KVM_CAP_COALESCED_MMIO.
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*/
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.ring = (void *)vcpu->run +
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(kvm_check_cap(KVM_CAP_COALESCED_MMIO) * getpagesize()),
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/*
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* The size of the I/O ring is fixed, but KVM defines the sized
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* based on the kernel's PAGE_SIZE. Thus, userspace must query
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* the host's page size at runtime to compute the ring size.
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*/
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.ring_size = (getpagesize() - sizeof(struct kvm_coalesced_mmio_ring)) /
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sizeof(struct kvm_coalesced_mmio),
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/*
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* Arbitrary address+port (MMIO mustn't overlap memslots), with
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* the MMIO GPA identity mapped in the guest.
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*/
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.mmio_gpa = 4ull * SZ_1G,
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.mmio = (uint64_t *)(4ull * SZ_1G),
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.pio_port = 0x80,
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};
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virt_map(vm, (uint64_t)kvm_builtin_io_ring.mmio, kvm_builtin_io_ring.mmio_gpa, 1);
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sync_global_to_guest(vm, kvm_builtin_io_ring);
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vcpu_args_set(vcpu, 1, &kvm_builtin_io_ring);
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for (i = 0; i < kvm_builtin_io_ring.ring_size; i++)
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test_coalesced_io(vcpu, &kvm_builtin_io_ring, i);
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kvm_vm_free(vm);
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return 0;
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}
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