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@xxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> --- arch/x86/kernel/kvm.c | 1 + arch/x86/kernel/kvmclock.c | 66 +++++++------------------------------- arch/x86/kernel/setup.c | 4 --- 3 files changed, 12 insertions(+), 59 deletions(-) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 5b2300b818af..c65c232d3ddd 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -628,6 +628,7 @@ const __initconst struct hypervisor_x86 x86_hyper_kvm = { .name = "KVM", .detect = kvm_detect, .type = X86_HYPER_KVM, + .init.init_platform = kvmclock_init, .init.guest_late_init = kvm_guest_init, .init.x2apic_available = kvm_para_available, }; 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; diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 2f86d883dd95..da1dbd99cb6e 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1197,10 +1197,6 @@ void __init setup_arch(char **cmdline_p) memblock_find_dma_reserve(); -#ifdef CONFIG_KVM_GUEST - kvmclock_init(); -#endif - tsc_early_delay_calibrate(); if (!early_xdbc_setup_hardware()) early_xdbc_register_console(); -- 2.18.0 -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html