From: David Matlack Introduce proc_util.c and proc_util.h to house utility functions for interacting with the proc filesystem. Add vfio_msix_to_host_irq(), which parses /proc/interrupts to map a VFIO device BDF and MSI-X vector to its corresponding host IRQ number. This helper will be used in a subsequent patch for debugging when implementing support for IRQ bypass in the KVM IRQ test. Suggested-by: Sean Christopherson Co-developed-by: Josh Hilke Signed-off-by: Josh Hilke Signed-off-by: David Matlack --- tools/testing/selftests/kvm/Makefile.kvm | 1 + .../testing/selftests/kvm/include/proc_util.h | 9 +++++ tools/testing/selftests/kvm/lib/proc_util.c | 40 +++++++++++++++++++ 3 files changed, 50 insertions(+) create mode 100644 tools/testing/selftests/kvm/include/proc_util.h create mode 100644 tools/testing/selftests/kvm/lib/proc_util.c diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index b859098121c7..63355b56c42f 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -11,6 +11,7 @@ LIBKVM += lib/kvm_util.c LIBKVM += lib/lru_gen_util.c LIBKVM += lib/memstress.c LIBKVM += lib/guest_sprintf.c +LIBKVM += lib/proc_util.c LIBKVM += lib/rbtree.c LIBKVM += lib/sparsebit.c LIBKVM += lib/test_util.c diff --git a/tools/testing/selftests/kvm/include/proc_util.h b/tools/testing/selftests/kvm/include/proc_util.h new file mode 100644 index 000000000000..704839b6d7af --- /dev/null +++ b/tools/testing/selftests/kvm/include/proc_util.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef SELFTEST_KVM_PROC_UTIL_H +#define SELFTEST_KVM_PROC_UTIL_H + +#include + +unsigned int vfio_msix_to_host_irq(const char *vfio_device_bdf, int msix); + +#endif /* SELFTEST_KVM_PROC_UTIL_H */ diff --git a/tools/testing/selftests/kvm/lib/proc_util.c b/tools/testing/selftests/kvm/lib/proc_util.c new file mode 100644 index 000000000000..84d30f055a0a --- /dev/null +++ b/tools/testing/selftests/kvm/lib/proc_util.c @@ -0,0 +1,40 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "kvm_util.h" +#include "test_util.h" +#include "proc_util.h" + +static FILE *open_proc_interrupts(void) +{ + FILE *fp; + + fp = fopen("/proc/interrupts", "r"); + TEST_ASSERT(fp, "fopen(/proc/interrupts) failed"); + + return fp; +} + +unsigned int vfio_msix_to_host_irq(const char *device_bdf, int msix) +{ + char search_string[64]; + char line[4096]; + int irq = -1; + FILE *fp; + + fp = open_proc_interrupts(); + + snprintf(search_string, sizeof(search_string), "vfio-msix[%d]", msix); + + while (fgets(line, sizeof(line), fp)) { + if (strstr(line, device_bdf) && strstr(line, search_string)) { + TEST_ASSERT_EQ(1, sscanf(line, "%d:", &irq)); + break; + } + } + + fclose(fp); + + TEST_ASSERT(irq != -1, "Failed to locate IRQ for %s %s", device_bdf, + search_string); + return (unsigned int)irq; +} + -- 2.54.0.1032.g2f8565e1d1-goog