From 93de2a6a4b91b72607136dd656edf03fb399d27f Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 23 Sep 2026 09:37:21 -0700 Subject: KVM: SEV: Do cache maintenance on the source VM during intra-host migration Manually perform cache maintenance on the source VM during intra-host migration to ensure no stale data is left in CPU caches after the VM is destroyed. Because the source VM is "converted" to a non-SEV VM, KVM's memory reclaim flows won't trigger cache maintenance, e.g. when all guest memory is reclaimed in response to detaching from the mmu_notifier. Note, relying on the destination VM to do cache maintenance isn't an option as KVM doesn't require identical guest memory configurations, i.e. the source VM may have access to memory that the destination VM does not. Enforcing equivalent memory configurations is infeasible, as it would require a *deep* comparison of memslots, e.g. to verify that not only are the memslot identical, but what the memslots point at is also identical. Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration") Cc: stable@vger.kernel.org Reported-by: Stefan Teodorescu Signed-off-by: Sean Christopherson Message-ID: <20260923163721.1584779-3-seanjc@google.com> Signed-off-by: Paolo Bonzini --- .../selftests/thermal/intel/power_floor/.gitignore | 1 + .../selftests/thermal/intel/power_floor/Makefile | 12 ++ .../thermal/intel/power_floor/power_floor_test.c | 108 ++++++++++++ .../thermal/intel/workload_hint/.gitignore | 1 + .../selftests/thermal/intel/workload_hint/Makefile | 12 ++ .../intel/workload_hint/workload_hint_test.c | 187 +++++++++++++++++++++ 6 files changed, 321 insertions(+) create mode 100644 tools/testing/selftests/thermal/intel/power_floor/.gitignore create mode 100644 tools/testing/selftests/thermal/intel/power_floor/Makefile create mode 100644 tools/testing/selftests/thermal/intel/power_floor/power_floor_test.c create mode 100644 tools/testing/selftests/thermal/intel/workload_hint/.gitignore create mode 100644 tools/testing/selftests/thermal/intel/workload_hint/Makefile create mode 100644 tools/testing/selftests/thermal/intel/workload_hint/workload_hint_test.c (limited to 'tools/testing/selftests/thermal') diff --git a/tools/testing/selftests/thermal/intel/power_floor/.gitignore b/tools/testing/selftests/thermal/intel/power_floor/.gitignore new file mode 100644 index 000000000..1b9a76406 --- /dev/null +++ b/tools/testing/selftests/thermal/intel/power_floor/.gitignore @@ -0,0 +1 @@ +power_floor_test diff --git a/tools/testing/selftests/thermal/intel/power_floor/Makefile b/tools/testing/selftests/thermal/intel/power_floor/Makefile new file mode 100644 index 000000000..07463c216 --- /dev/null +++ b/tools/testing/selftests/thermal/intel/power_floor/Makefile @@ -0,0 +1,12 @@ +# SPDX-License-Identifier: GPL-2.0 +ifndef CROSS_COMPILE +ARCH ?= $(shell uname -m 2>/dev/null || echo not) +override ARCH := $(shell echo $(ARCH) | sed -e s/i.86/x86/ -e s/x86_64/x86/) + +ifeq ($(ARCH),x86) +TEST_GEN_PROGS := power_floor_test + +include ../../../lib.mk + +endif +endif diff --git a/tools/testing/selftests/thermal/intel/power_floor/power_floor_test.c b/tools/testing/selftests/thermal/intel/power_floor/power_floor_test.c new file mode 100644 index 000000000..30cab5d42 --- /dev/null +++ b/tools/testing/selftests/thermal/intel/power_floor/power_floor_test.c @@ -0,0 +1,108 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include + +#define POWER_FLOOR_ENABLE_ATTRIBUTE "/sys/bus/pci/devices/0000:00:04.0/power_limits/power_floor_enable" +#define POWER_FLOOR_STATUS_ATTRIBUTE "/sys/bus/pci/devices/0000:00:04.0/power_limits/power_floor_status" + +void power_floor_exit(int signum) +{ + int fd; + + /* Disable feature via sysfs knob */ + + fd = open(POWER_FLOOR_ENABLE_ATTRIBUTE, O_RDWR); + if (fd < 0) { + perror("Unable to open power floor enable file\n"); + exit(1); + } + + if (write(fd, "0\n", 2) < 0) { + perror("Can' disable power floor notifications\n"); + exit(1); + } + + printf("Disabled power floor notifications\n"); + + close(fd); +} + +int main(int argc, char **argv) +{ + struct pollfd ufd; + char status_str[3]; + int fd, ret; + + if (signal(SIGINT, power_floor_exit) == SIG_IGN) + signal(SIGINT, SIG_IGN); + if (signal(SIGHUP, power_floor_exit) == SIG_IGN) + signal(SIGHUP, SIG_IGN); + if (signal(SIGTERM, power_floor_exit) == SIG_IGN) + signal(SIGTERM, SIG_IGN); + + /* Enable feature via sysfs knob */ + fd = open(POWER_FLOOR_ENABLE_ATTRIBUTE, O_RDWR); + if (fd < 0) { + perror("Unable to open power floor enable file\n"); + exit(1); + } + + if (write(fd, "1\n", 2) < 0) { + perror("Can't enable power floor notifications\n"); + exit(1); + } + + close(fd); + + printf("Enabled power floor notifications\n"); + + while (1) { + fd = open(POWER_FLOOR_STATUS_ATTRIBUTE, O_RDONLY); + if (fd < 0) { + perror("Unable to power floor status file\n"); + exit(1); + } + + if ((lseek(fd, 0L, SEEK_SET)) < 0) { + fprintf(stderr, "Failed to set pointer to beginning\n"); + exit(1); + } + + if (read(fd, status_str, sizeof(status_str)) < 0) { + fprintf(stderr, "Failed to read from:%s\n", + POWER_FLOOR_STATUS_ATTRIBUTE); + exit(1); + } + + ufd.fd = fd; + ufd.events = POLLPRI; + + ret = poll(&ufd, 1, -1); + if (ret < 0) { + perror("poll error"); + exit(1); + } else if (ret == 0) { + printf("Poll Timeout\n"); + } else { + if ((lseek(fd, 0L, SEEK_SET)) < 0) { + fprintf(stderr, "Failed to set pointer to beginning\n"); + exit(1); + } + + if (read(fd, status_str, sizeof(status_str)) < 0) + exit(0); + + printf("power floor status: %s\n", status_str); + } + + close(fd); + } +} diff --git a/tools/testing/selftests/thermal/intel/workload_hint/.gitignore b/tools/testing/selftests/thermal/intel/workload_hint/.gitignore new file mode 100644 index 000000000..d697b034a --- /dev/null +++ b/tools/testing/selftests/thermal/intel/workload_hint/.gitignore @@ -0,0 +1 @@ +workload_hint_test diff --git a/tools/testing/selftests/thermal/intel/workload_hint/Makefile b/tools/testing/selftests/thermal/intel/workload_hint/Makefile new file mode 100644 index 000000000..49e3bc2b2 --- /dev/null +++ b/tools/testing/selftests/thermal/intel/workload_hint/Makefile @@ -0,0 +1,12 @@ +# SPDX-License-Identifier: GPL-2.0 +ifndef CROSS_COMPILE +ARCH ?= $(shell uname -m 2>/dev/null || echo not) +override ARCH := $(shell echo $(ARCH) | sed -e s/i.86/x86/ -e s/x86_64/x86/) + +ifeq ($(ARCH),x86) +TEST_GEN_PROGS := workload_hint_test + +include ../../../lib.mk + +endif +endif diff --git a/tools/testing/selftests/thermal/intel/workload_hint/workload_hint_test.c b/tools/testing/selftests/thermal/intel/workload_hint/workload_hint_test.c new file mode 100644 index 000000000..569d44f22 --- /dev/null +++ b/tools/testing/selftests/thermal/intel/workload_hint/workload_hint_test.c @@ -0,0 +1,187 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include + +#define WORKLOAD_NOTIFICATION_DELAY_ATTRIBUTE "/sys/bus/pci/devices/0000:00:04.0/workload_hint/notification_delay_ms" +#define WORKLOAD_ENABLE_ATTRIBUTE "/sys/bus/pci/devices/0000:00:04.0/workload_hint/workload_hint_enable" +#define WORKLOAD_SLOW_ENABLE_ATTRIBUTE "/sys/bus/pci/devices/0000:00:04.0/workload_hint/workload_slow_hint_enable" +#define WORKLOAD_TYPE_INDEX_ATTRIBUTE "/sys/bus/pci/devices/0000:00:04.0/workload_hint/workload_type_index" + +static const char * const workload_types[] = { + "idle", + "battery_life", + "sustained", + "bursty", + NULL +}; + +static int wlt_slow; +static char *wlt_enable_attr; + +#define WORKLOAD_TYPE_MAX_INDEX 3 + +void workload_hint_exit(int signum) +{ + int fd; + + /* Disable feature via sysfs knob */ + + fd = open(wlt_enable_attr, O_RDWR); + if (fd < 0) { + perror("Unable to open workload type feature enable file"); + exit(1); + } + + if (write(fd, "0\n", 2) < 0) { + perror("Can't disable workload hints"); + exit(1); + } + + printf("Disabled workload type prediction\n"); + + close(fd); +} + +static void update_delay(char *delay_str) +{ + int fd; + + printf("Setting notification delay in ms to %s\n", delay_str); + + fd = open(WORKLOAD_NOTIFICATION_DELAY_ATTRIBUTE, O_RDWR); + if (fd < 0) { + perror("Unable to open workload notification delay"); + exit(1); + } + + if (write(fd, delay_str, strlen(delay_str)) < 0) { + perror("Can't set delay"); + exit(1); + } + + close(fd); +} + +int main(int argc, char **argv) +{ + struct pollfd ufd; + char index_str[4]; + int fd, ret, index; + char delay_str[64]; + int delay = 0; + + printf("Usage: workload_hint_test [notification delay in milli seconds][slow]\n"); + + if (argc > 1) { + int i; + + for (i = 1; i < argc; ++i) { + if (!strcmp(argv[i], "slow")) { + wlt_slow = 1; + continue; + } + + ret = sscanf(argv[1], "%d", &delay); + if (ret < 0) { + printf("Invalid delay\n"); + exit(1); + } + + sprintf(delay_str, "%s\n", argv[1]); + update_delay(delay_str); + } + } + + if (signal(SIGINT, workload_hint_exit) == SIG_IGN) + signal(SIGINT, SIG_IGN); + if (signal(SIGHUP, workload_hint_exit) == SIG_IGN) + signal(SIGHUP, SIG_IGN); + if (signal(SIGTERM, workload_hint_exit) == SIG_IGN) + signal(SIGTERM, SIG_IGN); + + if (wlt_slow) + wlt_enable_attr = WORKLOAD_SLOW_ENABLE_ATTRIBUTE; + else + wlt_enable_attr = WORKLOAD_ENABLE_ATTRIBUTE; + + /* Enable feature via sysfs knob */ + fd = open(wlt_enable_attr, O_RDWR); + if (fd < 0) { + perror("Unable to open workload type feature enable file"); + exit(1); + } + + if (write(fd, "1\n", 2) < 0) { + perror("Can't enable workload hints"); + exit(1); + } + + close(fd); + + printf("Enabled workload type prediction\n"); + + while (1) { + fd = open(WORKLOAD_TYPE_INDEX_ATTRIBUTE, O_RDONLY); + if (fd < 0) { + perror("Unable to open workload type file"); + exit(1); + } + + if ((lseek(fd, 0L, SEEK_SET)) < 0) { + fprintf(stderr, "Failed to set pointer to beginning\n"); + exit(1); + } + + if (read(fd, index_str, sizeof(index_str)) < 0) { + fprintf(stderr, "Failed to read from:%s\n", + WORKLOAD_TYPE_INDEX_ATTRIBUTE); + exit(1); + } + + ufd.fd = fd; + ufd.events = POLLPRI; + + ret = poll(&ufd, 1, -1); + if (ret < 0) { + perror("poll error"); + exit(1); + } else if (ret == 0) { + printf("Poll Timeout\n"); + } else { + if ((lseek(fd, 0L, SEEK_SET)) < 0) { + fprintf(stderr, "Failed to set pointer to beginning\n"); + exit(1); + } + + if (read(fd, index_str, sizeof(index_str)) < 0) + exit(0); + + ret = sscanf(index_str, "%d", &index); + if (ret < 0) + break; + + if (wlt_slow) { + if (index & 0x10) + printf("workload type slow:%s\n", "power"); + else + printf("workload type slow:%s\n", "performance"); + } + + index &= 0x0f; + if (index > WORKLOAD_TYPE_MAX_INDEX) + printf("Invalid workload type index\n"); + else + printf("workload type:%s\n", workload_types[index]); + } + + close(fd); + } +} -- cgit v1.3.1