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authorPavel Tatashin <pasha.tatashin@oracle.com>2018-07-19 16:55:20 -0400
committerThomas Gleixner <tglx@linutronix.de>2018-07-20 00:02:36 +0200
commit368a540e0232ad446931f5a4e8a5e06f69f21343 (patch)
tree8724da6be43dd468ab751d9208f93656f06aae5d /arch/x86/kernel/kvmclock.c
parent73ab603f44149ff48889d5109ea9ab64bf38cc69 (diff)
downloadlinux-368a540e0232ad446931f5a4e8a5e06f69f21343.tar.bz2
x86/kvmclock: Remove memblock dependency
KVM clock is initialized later compared to other hypervisor clocks because it has a dependency on the memblock allocator. Bring it in line with other hypervisors by using memory from the BSS instead of allocating it. The benefits: - Remove ifdef from common code - Earlier availability of the clock - Remove dependency on memblock, and reduce code The downside: - Static allocation of the per cpu data structures sized NR_CPUS * 64byte Will be addressed in follow up patches. [ tglx: Split out from larger series ] Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Cc: linux@armlinux.org.uk Cc: schwidefsky@de.ibm.com Cc: heiko.carstens@de.ibm.com Cc: john.stultz@linaro.org Cc: sboyd@codeaurora.org Cc: hpa@zytor.com Cc: douly.fnst@cn.fujitsu.com Cc: peterz@infradead.org Cc: prarit@redhat.com Cc: feng.tang@intel.com Cc: pmladek@suse.com Cc: gnomes@lxorguk.ukuu.org.uk Cc: linux-s390@vger.kernel.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Link: https://lkml.kernel.org/r/20180719205545.16512-2-pasha.tatashin@oracle.com
Diffstat (limited to 'arch/x86/kernel/kvmclock.c')
-rw-r--r--arch/x86/kernel/kvmclock.c66
1 files changed, 11 insertions, 55 deletions
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 3b8e7c13c614..1f6ac5aaa904 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -23,9 +23,9 @@
#include <asm/apic.h>
#include <linux/percpu.h>
#include <linux/hardirq.h>
-#include <linux/memblock.h>
#include <linux/sched.h>
#include <linux/sched/clock.h>
+#include <linux/mm.h>
#include <asm/mem_encrypt.h>
#include <asm/x86_init.h>
@@ -44,6 +44,13 @@ static int parse_no_kvmclock(char *arg)
}
early_param("no-kvmclock", parse_no_kvmclock);
+/* Aligned to page sizes to match whats mapped via vsyscalls to userspace */
+#define HV_CLOCK_SIZE (sizeof(struct pvclock_vsyscall_time_info) * NR_CPUS)
+#define WALL_CLOCK_SIZE (sizeof(struct pvclock_wall_clock))
+
+static u8 hv_clock_mem[PAGE_ALIGN(HV_CLOCK_SIZE)] __aligned(PAGE_SIZE);
+static u8 wall_clock_mem[PAGE_ALIGN(WALL_CLOCK_SIZE)] __aligned(PAGE_SIZE);
+
/* The hypervisor will put information about time periodically here */
static struct pvclock_vsyscall_time_info *hv_clock;
static struct pvclock_wall_clock *wall_clock;
@@ -245,43 +252,12 @@ static void kvm_shutdown(void)
native_machine_shutdown();
}
-static phys_addr_t __init kvm_memblock_alloc(phys_addr_t size,
- phys_addr_t align)
-{
- phys_addr_t mem;
-
- mem = memblock_alloc(size, align);
- if (!mem)
- return 0;
-
- if (sev_active()) {
- if (early_set_memory_decrypted((unsigned long)__va(mem), size))
- goto e_free;
- }
-
- return mem;
-e_free:
- memblock_free(mem, size);
- return 0;
-}
-
-static void __init kvm_memblock_free(phys_addr_t addr, phys_addr_t size)
-{
- if (sev_active())
- early_set_memory_encrypted((unsigned long)__va(addr), size);
-
- memblock_free(addr, size);
-}
-
void __init kvmclock_init(void)
{
struct pvclock_vcpu_time_info *vcpu_time;
- unsigned long mem, mem_wall_clock;
- int size, cpu, wall_clock_size;
+ int cpu;
u8 flags;
- size = PAGE_ALIGN(sizeof(struct pvclock_vsyscall_time_info)*NR_CPUS);
-
if (!kvm_para_available())
return;
@@ -291,28 +267,11 @@ void __init kvmclock_init(void)
} else if (!(kvmclock && kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE)))
return;
- wall_clock_size = PAGE_ALIGN(sizeof(struct pvclock_wall_clock));
- mem_wall_clock = kvm_memblock_alloc(wall_clock_size, PAGE_SIZE);
- if (!mem_wall_clock)
- return;
-
- wall_clock = __va(mem_wall_clock);
- memset(wall_clock, 0, wall_clock_size);
-
- mem = kvm_memblock_alloc(size, PAGE_SIZE);
- if (!mem) {
- kvm_memblock_free(mem_wall_clock, wall_clock_size);
- wall_clock = NULL;
- return;
- }
-
- hv_clock = __va(mem);
- memset(hv_clock, 0, size);
+ wall_clock = (struct pvclock_wall_clock *)wall_clock_mem;
+ hv_clock = (struct pvclock_vsyscall_time_info *)hv_clock_mem;
if (kvm_register_clock("primary cpu clock")) {
hv_clock = NULL;
- kvm_memblock_free(mem, size);
- kvm_memblock_free(mem_wall_clock, wall_clock_size);
wall_clock = NULL;
return;
}
@@ -357,13 +316,10 @@ int __init kvm_setup_vsyscall_timeinfo(void)
int cpu;
u8 flags;
struct pvclock_vcpu_time_info *vcpu_time;
- unsigned int size;
if (!hv_clock)
return 0;
- size = PAGE_ALIGN(sizeof(struct pvclock_vsyscall_time_info)*NR_CPUS);
-
cpu = get_cpu();
vcpu_time = &hv_clock[cpu].pvti;