From 368a540e0232ad446931f5a4e8a5e06f69f21343 Mon Sep 17 00:00:00 2001 From: Pavel Tatashin Date: Thu, 19 Jul 2018 16:55:20 -0400 Subject: 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 Signed-off-by: Thomas Gleixner Acked-by: Paolo Bonzini 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 --- arch/x86/kernel/kvmclock.c | 66 ++++++++-------------------------------------- 1 file changed, 11 insertions(+), 55 deletions(-) (limited to 'arch/x86/kernel/kvmclock.c') 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 #include #include -#include #include #include +#include #include #include @@ -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; -- cgit