diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 51375e766e90..fd006a272024 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -736,7 +736,6 @@ struct kvm_arch{ wait_queue_head_t ipte_wq; int ipte_lock_count; struct mutex ipte_mutex; - struct ratelimit_state sthyi_limit; spinlock_t start_stop_lock; struct sie_page2 *sie_page2; struct kvm_s390_cpu_model model; diff --git a/arch/s390/include/asm/sysinfo.h b/arch/s390/include/asm/sysinfo.h index 0f09135f0ae4..a702cb9d4269 100644 --- a/arch/s390/include/asm/sysinfo.h +++ b/arch/s390/include/asm/sysinfo.h @@ -199,4 +199,5 @@ struct service_level { int register_service_level(struct service_level *); int unregister_service_level(struct service_level *); +int sthyi_fill(void *dst, u64 *rc); #endif /* __ASM_S390_SYSINFO_H */ diff --git a/arch/s390/include/uapi/asm/sthyi.h b/arch/s390/include/uapi/asm/sthyi.h new file mode 100644 index 000000000000..ec113db4eb7e --- /dev/null +++ b/arch/s390/include/uapi/asm/sthyi.h @@ -0,0 +1,6 @@ +#ifndef _UAPI_ASM_STHYI_H +#define _UAPI_ASM_STHYI_H + +#define STHYI_FC_CP_IFL_CAP 0 + +#endif /* _UAPI_ASM_STHYI_H */ diff --git a/arch/s390/include/uapi/asm/unistd.h b/arch/s390/include/uapi/asm/unistd.h index ea42290e7d51..61c64f543769 100644 --- a/arch/s390/include/uapi/asm/unistd.h +++ b/arch/s390/include/uapi/asm/unistd.h @@ -315,7 +315,8 @@ #define __NR_pwritev2 377 #define __NR_s390_guarded_storage 378 #define __NR_statx 379 -#define NR_syscalls 380 +#define __NR_s390_sthyi 380 +#define NR_syscalls 381 /* * There are some system calls that are not present on 64 bit, some diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index 9118e62f9fca..7b742ffac7d3 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -57,7 +57,7 @@ obj-y := traps.o time.o process.o base.o early.o setup.o idle.o vtime.o obj-y += processor.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o obj-y += debug.o irq.o ipl.o dis.o diag.o vdso.o als.o obj-y += sysinfo.o jump_label.o lgr.o os_info.o machine_kexec.o pgm_check.o -obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o +obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o obj-y += entry.o reipl.o relocate_kernel.o kdebugfs.o extra-y += head.o head64.o vmlinux.lds diff --git a/arch/s390/kernel/compat_wrapper.c b/arch/s390/kernel/compat_wrapper.c index 986642a3543b..eb0b17ed95b6 100644 --- a/arch/s390/kernel/compat_wrapper.c +++ b/arch/s390/kernel/compat_wrapper.c @@ -180,3 +180,4 @@ COMPAT_SYSCALL_WRAP3(mlock2, unsigned long, start, size_t, len, int, flags); COMPAT_SYSCALL_WRAP6(copy_file_range, int, fd_in, loff_t __user *, off_in, int, fd_out, loff_t __user *, off_out, size_t, len, unsigned int, flags); COMPAT_SYSCALL_WRAP2(s390_guarded_storage, int, command, struct gs_cb *, gs_cb); COMPAT_SYSCALL_WRAP5(statx, int, dfd, const char __user *, path, unsigned, flags, unsigned, mask, struct statx __user *, buffer); +COMPAT_SYSCALL_WRAP4(s390_sthyi, unsigned long, code, void __user *, info, u64 __user *, rc, unsigned long, flags); diff --git a/arch/s390/kernel/entry.h b/arch/s390/kernel/entry.h index dbf5f7e18246..bb5301eeb4f4 100644 --- a/arch/s390/kernel/entry.h +++ b/arch/s390/kernel/entry.h @@ -77,6 +77,7 @@ long sys_s390_runtime_instr(int command, int signum); long sys_s390_guarded_storage(int command, struct gs_cb __user *); long sys_s390_pci_mmio_write(unsigned long, const void __user *, size_t); long sys_s390_pci_mmio_read(unsigned long, void __user *, size_t); +long sys_s390_sthyi(unsigned long function_code, void __user *buffer, u64 __user *return_code, unsigned long flags); DECLARE_PER_CPU(u64, mt_cycles[8]); diff --git a/arch/s390/kvm/sthyi.c b/arch/s390/kernel/sthyi.c similarity index 77% rename from arch/s390/kvm/sthyi.c rename to arch/s390/kernel/sthyi.c index 395926b8c1ed..12981e197f01 100644 --- a/arch/s390/kvm/sthyi.c +++ b/arch/s390/kernel/sthyi.c @@ -8,22 +8,19 @@ * Copyright IBM Corp. 2016 * Author(s): Janosch Frank */ -#include #include #include #include -#include - -#include +#include +#include #include #include #include #include #include - -#include "kvm-s390.h" -#include "gaccess.h" -#include "trace.h" +#include +#include +#include "entry.h" #define DED_WEIGHT 0xffff /* @@ -144,6 +141,21 @@ struct lpar_cpu_inf { struct cpu_inf ifl; }; +/* + * STHYI requires extensive locking in the higher hypervisors + * and is very computational/memory expensive. Therefore we + * cache the retrieved data whose valid period is 1s. + */ +#define CACHE_VALID_JIFFIES HZ + +struct sthyi_info { + void *info; + unsigned long end; +}; + +static DEFINE_MUTEX(sthyi_mutex); +static struct sthyi_info sthyi_cache; + static inline u64 cpu_id(u8 ctidx, void *diag224_buf) { return *((u64 *)(diag224_buf + (ctidx + 1) * DIAG204_CPU_NAME_LEN)); @@ -382,88 +394,124 @@ out: vfree(diag204_buf); } -static int sthyi(u64 vaddr) +static int sthyi(u64 vaddr, u64 *rc) { register u64 code asm("0") = 0; register u64 addr asm("2") = vaddr; + register u64 rcode asm("3"); int cc; asm volatile( ".insn rre,0xB2560000,%[code],%[addr]\n" "ipm %[cc]\n" "srl %[cc],28\n" - : [cc] "=d" (cc) + : [cc] "=d" (cc), "=d" (rcode) : [code] "d" (code), [addr] "a" (addr) - : "3", "memory", "cc"); + : "memory", "cc"); + *rc = rcode; return cc; } -int handle_sthyi(struct kvm_vcpu *vcpu) +static int fill_dst(void *dst, u64 *rc) { - int reg1, reg2, r = 0; - u64 code, addr, cc = 0; - struct sthyi_sctns *sctns = NULL; - - if (!test_kvm_facility(vcpu->kvm, 74)) - return kvm_s390_inject_program_int(vcpu, PGM_OPERATION); + struct sthyi_sctns *sctns = (struct sthyi_sctns *)dst; /* - * STHYI requires extensive locking in the higher hypervisors - * and is very computational/memory expensive. Therefore we - * ratelimit the executions per VM. + * If the facility is on, we don't want to emulate the instruction. + * We ask the hypervisor to provide the data. */ - if (!__ratelimit(&vcpu->kvm->arch.sthyi_limit)) { - kvm_s390_retry_instr(vcpu); - return 0; - } - - kvm_s390_get_regs_rre(vcpu, ®1, ®2); - code = vcpu->run->s.regs.gprs[reg1]; - addr = vcpu->run->s.regs.gprs[reg2]; - - vcpu->stat.instruction_sthyi++; - VCPU_EVENT(vcpu, 3, "STHYI: fc: %llu addr: 0x%016llx", code, addr); - trace_kvm_s390_handle_sthyi(vcpu, code, addr); - - if (reg1 == reg2 || reg1 & 1 || reg2 & 1) - return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); - - if (code & 0xffff) { - cc = 3; - goto out; - } - - if (addr & ~PAGE_MASK) - return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); - - sctns = (void *)get_zeroed_page(GFP_KERNEL); - if (!sctns) - return -ENOMEM; - - /* - * If we are a guest, we don't want to emulate an emulated - * instruction. We ask the hypervisor to provide the data. - */ - if (test_facility(74)) { - cc = sthyi((u64)sctns); - goto out; - } + if (test_facility(74)) + return sthyi((u64)dst, rc); fill_hdr(sctns); fill_stsi(sctns); fill_diag(sctns); + *rc = 0; + return 0; +} -out: - if (!cc) { - r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE); - if (r) { - free_page((unsigned long)sctns); - return kvm_s390_inject_prog_cond(vcpu, r); - } - } +static int sthyi_init_cache(void) +{ + if (sthyi_cache.info) + return 0; + sthyi_cache.info = (void *)get_zeroed_page(GFP_KERNEL); + if (!sthyi_cache.info) + return -ENOMEM; + sthyi_cache.end = jiffies - 1; /* expired */ + return 0; +} - free_page((unsigned long)sctns); - vcpu->run->s.regs.gprs[reg2 + 1] = cc ? 4 : 0; - kvm_s390_set_psw_cc(vcpu, cc); +static int sthyi_update_cache(u64 *rc) +{ + int r; + + memset(sthyi_cache.info, 0, PAGE_SIZE); + r = fill_dst(sthyi_cache.info, rc); + if (r) + return r; + sthyi_cache.end = jiffies + CACHE_VALID_JIFFIES; + return r; +} + +/* + * sthyi_fill - Fill page with data returned by the STHYI instruction + * + * @dst: Pointer to zeroed page + * @rc: Pointer for storing the return code of the instruction + * + * Fills the destination with system information returned by the STHYI + * instruction. The data is generated by emulation or execution of STHYI, + * if available. The return value is the condition code that would be + * returned, the rc parameter is the return code which is passed in + * register R2 + 1. + */ +int sthyi_fill(void *dst, u64 *rc) +{ + int r; + + mutex_lock(&sthyi_mutex); + r = sthyi_init_cache(); + if (r) + goto out; + + if (time_is_before_jiffies(sthyi_cache.end)) { + /* cache expired */ + r = sthyi_update_cache(rc); + if (r) + goto out; + } + *rc = 0; + memcpy(dst, sthyi_cache.info, PAGE_SIZE); +out: + mutex_unlock(&sthyi_mutex); + return r; +} +EXPORT_SYMBOL_GPL(sthyi_fill); + +SYSCALL_DEFINE4(s390_sthyi, unsigned long, function_code, void __user *, buffer, + u64 __user *, return_code, unsigned long, flags) +{ + u64 sthyi_rc; + void *info; + int r; + + if (flags) + return -EINVAL; + if (function_code != STHYI_FC_CP_IFL_CAP) + return -EOPNOTSUPP; + info = (void *)get_zeroed_page(GFP_KERNEL); + if (!info) + return -ENOMEM; + r = sthyi_fill(info, &sthyi_rc); + if (r < 0) + goto out; + if (return_code && put_user(sthyi_rc, return_code)) { + r = -EFAULT; + goto out; + } + if (copy_to_user(buffer, info, PAGE_SIZE)) + r = -EFAULT; +out: + free_page((unsigned long)info); return r; } diff --git a/arch/s390/kernel/syscalls.S b/arch/s390/kernel/syscalls.S index 54fce7b065de..0fb407ebbf46 100644 --- a/arch/s390/kernel/syscalls.S +++ b/arch/s390/kernel/syscalls.S @@ -388,3 +388,4 @@ SYSCALL(sys_preadv2,compat_sys_preadv2) SYSCALL(sys_pwritev2,compat_sys_pwritev2) SYSCALL(sys_s390_guarded_storage,compat_sys_s390_guarded_storage) /* 378 */ SYSCALL(sys_statx,compat_sys_statx) +SYSCALL(sys_s390_sthyi,compat_sys_s390_sthyi) diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile index 09a9e6dfc09f..6048b1c6e580 100644 --- a/arch/s390/kvm/Makefile +++ b/arch/s390/kvm/Makefile @@ -12,6 +12,6 @@ common-objs = $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/async_pf.o $(KVM)/irqch ccflags-y := -Ivirt/kvm -Iarch/s390/kvm kvm-objs := $(common-objs) kvm-s390.o intercept.o interrupt.o priv.o sigp.o -kvm-objs += diag.o gaccess.o guestdbg.o sthyi.o vsie.o +kvm-objs += diag.o gaccess.o guestdbg.o vsie.o obj-$(CONFIG_KVM) += kvm.o diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c index a4752bf6b526..8fe034beb623 100644 --- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "kvm-s390.h" #include "gaccess.h" @@ -360,6 +361,61 @@ static int handle_partial_execution(struct kvm_vcpu *vcpu) return -EOPNOTSUPP; } +/* + * Handle the sthyi instruction that provides the guest with system + * information, like current CPU resources available at each level of + * the machine. + */ +int handle_sthyi(struct kvm_vcpu *vcpu) +{ + int reg1, reg2, r = 0; + u64 code, addr, cc = 0, rc = 0; + struct sthyi_sctns *sctns = NULL; + + if (!test_kvm_facility(vcpu->kvm, 74)) + return kvm_s390_inject_program_int(vcpu, PGM_OPERATION); + + kvm_s390_get_regs_rre(vcpu, ®1, ®2); + code = vcpu->run->s.regs.gprs[reg1]; + addr = vcpu->run->s.regs.gprs[reg2]; + + vcpu->stat.instruction_sthyi++; + VCPU_EVENT(vcpu, 3, "STHYI: fc: %llu addr: 0x%016llx", code, addr); + trace_kvm_s390_handle_sthyi(vcpu, code, addr); + + if (reg1 == reg2 || reg1 & 1 || reg2 & 1) + return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); + + if (code & 0xffff) { + cc = 3; + rc = 4; + goto out; + } + + if (addr & ~PAGE_MASK) + return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); + + sctns = (void *)get_zeroed_page(GFP_KERNEL); + if (!sctns) + return -ENOMEM; + + cc = sthyi_fill(sctns, &rc); + +out: + if (!cc) { + r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE); + if (r) { + free_page((unsigned long)sctns); + return kvm_s390_inject_prog_cond(vcpu, r); + } + } + + free_page((unsigned long)sctns); + vcpu->run->s.regs.gprs[reg2 + 1] = rc; + kvm_s390_set_psw_cc(vcpu, cc); + return r; +} + static int handle_operexc(struct kvm_vcpu *vcpu) { psw_t oldpsw, newpsw; diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 3f8316c2cb2a..4bc70afe0a10 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -1884,8 +1884,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) rc = -ENOMEM; - ratelimit_state_init(&kvm->arch.sthyi_limit, 5 * HZ, 500); - kvm->arch.use_esca = 0; /* start with basic SCA */ if (!sclp.has_64bscao) alloc_flags |= GFP_DMA; diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index 9f8fdd7b2311..10d65dfbc306 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -242,6 +242,8 @@ static inline void kvm_s390_retry_instr(struct kvm_vcpu *vcpu) kvm_s390_rewind_psw(vcpu, kvm_s390_get_ilen(vcpu)); } +int handle_sthyi(struct kvm_vcpu *vcpu); + /* implemented in priv.c */ int is_valid_psw(psw_t *psw); int kvm_s390_handle_aa(struct kvm_vcpu *vcpu); @@ -268,9 +270,6 @@ void kvm_s390_vsie_destroy(struct kvm *kvm); int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu); int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu); -/* implemented in sthyi.c */ -int handle_sthyi(struct kvm_vcpu *vcpu); - /* implemented in kvm-s390.c */ void kvm_s390_set_tod_clock_ext(struct kvm *kvm, const struct kvm_s390_vm_tod_clock *gtod);