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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/ptp/ptp_kvm_x86.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/ptp/ptp_kvm_x86.c')
-rw-r--r--drivers/ptp/ptp_kvm_x86.c129
1 files changed, 129 insertions, 0 deletions
diff --git a/drivers/ptp/ptp_kvm_x86.c b/drivers/ptp/ptp_kvm_x86.c
new file mode 100644
index 0000000000..902844cc1a
--- /dev/null
+++ b/drivers/ptp/ptp_kvm_x86.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Virtual PTP 1588 clock for use with KVM guests
+ *
+ * Copyright (C) 2017 Red Hat Inc.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <asm/pvclock.h>
+#include <asm/kvmclock.h>
+#include <linux/module.h>
+#include <uapi/asm/kvm_para.h>
+#include <uapi/linux/kvm_para.h>
+#include <linux/ptp_clock_kernel.h>
+#include <linux/ptp_kvm.h>
+#include <linux/set_memory.h>
+
+static phys_addr_t clock_pair_gpa;
+static struct kvm_clock_pairing clock_pair_glbl;
+static struct kvm_clock_pairing *clock_pair;
+
+int kvm_arch_ptp_init(void)
+{
+ struct page *p;
+ long ret;
+
+ if (!kvm_para_available())
+ return -ENODEV;
+
+ if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) {
+ p = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!p)
+ return -ENOMEM;
+
+ clock_pair = page_address(p);
+ ret = set_memory_decrypted((unsigned long)clock_pair, 1);
+ if (ret) {
+ __free_page(p);
+ clock_pair = NULL;
+ goto nofree;
+ }
+ } else {
+ clock_pair = &clock_pair_glbl;
+ }
+
+ clock_pair_gpa = slow_virt_to_phys(clock_pair);
+ if (!pvclock_get_pvti_cpu0_va()) {
+ ret = -ENODEV;
+ goto err;
+ }
+
+ ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, clock_pair_gpa,
+ KVM_CLOCK_PAIRING_WALLCLOCK);
+ if (ret == -KVM_ENOSYS) {
+ ret = -ENODEV;
+ goto err;
+ }
+
+ return ret;
+
+err:
+ kvm_arch_ptp_exit();
+nofree:
+ return ret;
+}
+
+void kvm_arch_ptp_exit(void)
+{
+ if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) {
+ WARN_ON(set_memory_encrypted((unsigned long)clock_pair, 1));
+ free_page((unsigned long)clock_pair);
+ clock_pair = NULL;
+ }
+}
+
+int kvm_arch_ptp_get_clock(struct timespec64 *ts)
+{
+ long ret;
+
+ ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING,
+ clock_pair_gpa,
+ KVM_CLOCK_PAIRING_WALLCLOCK);
+ if (ret != 0) {
+ pr_err_ratelimited("clock offset hypercall ret %lu\n", ret);
+ return -EOPNOTSUPP;
+ }
+
+ ts->tv_sec = clock_pair->sec;
+ ts->tv_nsec = clock_pair->nsec;
+
+ return 0;
+}
+
+int kvm_arch_ptp_get_crosststamp(u64 *cycle, struct timespec64 *tspec,
+ struct clocksource **cs)
+{
+ struct pvclock_vcpu_time_info *src;
+ unsigned int version;
+ long ret;
+
+ src = this_cpu_pvti();
+
+ do {
+ /*
+ * We are using a TSC value read in the hosts
+ * kvm_hc_clock_pairing handling.
+ * So any changes to tsc_to_system_mul
+ * and tsc_shift or any other pvclock
+ * data invalidate that measurement.
+ */
+ version = pvclock_read_begin(src);
+
+ ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING,
+ clock_pair_gpa,
+ KVM_CLOCK_PAIRING_WALLCLOCK);
+ if (ret != 0) {
+ pr_err_ratelimited("clock pairing hypercall ret %lu\n", ret);
+ return -EOPNOTSUPP;
+ }
+ tspec->tv_sec = clock_pair->sec;
+ tspec->tv_nsec = clock_pair->nsec;
+ *cycle = __pvclock_read_cycles(src, clock_pair->tsc);
+ } while (pvclock_read_retry(src, version));
+
+ *cs = &kvm_clock;
+
+ return 0;
+}