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Diffstat (limited to 'arch/x86/kernel/kvmclock.c')
-rw-r--r--arch/x86/kernel/kvmclock.c52
1 files changed, 49 insertions, 3 deletions
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 1e6764648af3..013fe3d21dbb 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -28,6 +28,7 @@
#include <linux/sched/clock.h>
#include <linux/mm.h>
#include <linux/slab.h>
+#include <linux/set_memory.h>
#include <asm/hypervisor.h>
#include <asm/mem_encrypt.h>
@@ -61,9 +62,10 @@ early_param("no-kvmclock-vsyscall", parse_no_kvmclock_vsyscall);
(PAGE_SIZE / sizeof(struct pvclock_vsyscall_time_info))
static struct pvclock_vsyscall_time_info
- hv_clock_boot[HVC_BOOT_ARRAY_SIZE] __aligned(PAGE_SIZE);
-static struct pvclock_wall_clock wall_clock;
+ hv_clock_boot[HVC_BOOT_ARRAY_SIZE] __bss_decrypted __aligned(PAGE_SIZE);
+static struct pvclock_wall_clock wall_clock __bss_decrypted;
static DEFINE_PER_CPU(struct pvclock_vsyscall_time_info *, hv_clock_per_cpu);
+static struct pvclock_vsyscall_time_info *hvclock_mem;
static inline struct pvclock_vcpu_time_info *this_cpu_pvti(void)
{
@@ -236,6 +238,45 @@ static void kvm_shutdown(void)
native_machine_shutdown();
}
+static void __init kvmclock_init_mem(void)
+{
+ unsigned long ncpus;
+ unsigned int order;
+ struct page *p;
+ int r;
+
+ if (HVC_BOOT_ARRAY_SIZE >= num_possible_cpus())
+ return;
+
+ ncpus = num_possible_cpus() - HVC_BOOT_ARRAY_SIZE;
+ order = get_order(ncpus * sizeof(*hvclock_mem));
+
+ p = alloc_pages(GFP_KERNEL, order);
+ if (!p) {
+ pr_warn("%s: failed to alloc %d pages", __func__, (1U << order));
+ return;
+ }
+
+ hvclock_mem = page_address(p);
+
+ /*
+ * hvclock is shared between the guest and the hypervisor, must
+ * be mapped decrypted.
+ */
+ if (sev_active()) {
+ r = set_memory_decrypted((unsigned long) hvclock_mem,
+ 1UL << order);
+ if (r) {
+ __free_pages(p, order);
+ hvclock_mem = NULL;
+ pr_warn("kvmclock: set_memory_decrypted() failed. Disabling\n");
+ return;
+ }
+ }
+
+ memset(hvclock_mem, 0, PAGE_SIZE << order);
+}
+
static int __init kvm_setup_vsyscall_timeinfo(void)
{
#ifdef CONFIG_X86_64
@@ -250,6 +291,9 @@ static int __init kvm_setup_vsyscall_timeinfo(void)
kvm_clock.archdata.vclock_mode = VCLOCK_PVCLOCK;
#endif
+
+ kvmclock_init_mem();
+
return 0;
}
early_initcall(kvm_setup_vsyscall_timeinfo);
@@ -269,8 +313,10 @@ static int kvmclock_setup_percpu(unsigned int cpu)
/* Use the static page for the first CPUs, allocate otherwise */
if (cpu < HVC_BOOT_ARRAY_SIZE)
p = &hv_clock_boot[cpu];
+ else if (hvclock_mem)
+ p = hvclock_mem + cpu - HVC_BOOT_ARRAY_SIZE;
else
- p = kzalloc(sizeof(*p), GFP_KERNEL);
+ return -ENOMEM;
per_cpu(hv_clock_per_cpu, cpu) = p;
return p ? 0 : -ENOMEM;