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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2017-10-09 11:16:49 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2017-10-09 11:16:49 +0200
commit3bdf5679c9e46088a0d677e795afc92b5f77940f (patch)
treebe5a99e62b5ff078413d71297154ece9f724ec9e
parent91a1fad759ffd616b836984ca0420c7ad5996eef (diff)
parent3d8757b87d7fc15a87928bc970f060bc9c6dc618 (diff)
Merge branch 'sthyi' into features
Add the store-hypervisor-information code into features using a tip branch for parallel merging into the KVM tree.
-rw-r--r--arch/s390/include/asm/kvm_host.h1
-rw-r--r--arch/s390/include/asm/sysinfo.h1
-rw-r--r--arch/s390/include/uapi/asm/sthyi.h6
-rw-r--r--arch/s390/include/uapi/asm/unistd.h3
-rw-r--r--arch/s390/kernel/Makefile2
-rw-r--r--arch/s390/kernel/compat_wrapper.c1
-rw-r--r--arch/s390/kernel/entry.h1
-rw-r--r--arch/s390/kernel/sthyi.c (renamed from arch/s390/kvm/sthyi.c)172
-rw-r--r--arch/s390/kernel/syscalls.S1
-rw-r--r--arch/s390/kvm/Makefile2
-rw-r--r--arch/s390/kvm/intercept.c56
-rw-r--r--arch/s390/kvm/kvm-s390.c2
-rw-r--r--arch/s390/kvm/kvm-s390.h5
13 files changed, 182 insertions, 71 deletions
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
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 <frankja@linux.vnet.ibm.com>
*/
-#include <linux/kvm_host.h>
#include <linux/errno.h>
#include <linux/pagemap.h>
#include <linux/vmalloc.h>
-#include <linux/ratelimit.h>
-
-#include <asm/kvm_host.h>
+#include <linux/syscalls.h>
+#include <linux/mutex.h>
#include <asm/asm-offsets.h>
#include <asm/sclp.h>
#include <asm/diag.h>
#include <asm/sysinfo.h>
#include <asm/ebcdic.h>
-
-#include "kvm-s390.h"
-#include "gaccess.h"
-#include "trace.h"
+#include <asm/facility.h>
+#include <asm/sthyi.h>
+#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);
+ if (test_facility(74))
+ return sthyi((u64)dst, rc);
+
+ fill_hdr(sctns);
+ fill_stsi(sctns);
+ fill_diag(sctns);
+ *rc = 0;
+ return 0;
+}
+
+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;
+}
- kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
- code = vcpu->run->s.regs.gprs[reg1];
- addr = vcpu->run->s.regs.gprs[reg2];
+static int sthyi_update_cache(u64 *rc)
+{
+ int r;
- vcpu->stat.instruction_sthyi++;
- VCPU_EVENT(vcpu, 3, "STHYI: fc: %llu addr: 0x%016llx", code, addr);
- trace_kvm_s390_handle_sthyi(vcpu, code, addr);
+ 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;
+}
- if (reg1 == reg2 || reg1 & 1 || reg2 & 1)
- return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+/*
+ * 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;
- if (code & 0xffff) {
- cc = 3;
+ mutex_lock(&sthyi_mutex);
+ r = sthyi_init_cache();
+ if (r)
goto out;
- }
- if (addr & ~PAGE_MASK)
- return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+ 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);
- sctns = (void *)get_zeroed_page(GFP_KERNEL);
- if (!sctns)
+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;
-
- /*
- * 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);
+ r = sthyi_fill(info, &sthyi_rc);
+ if (r < 0)
+ goto out;
+ if (return_code && put_user(sthyi_rc, return_code)) {
+ r = -EFAULT;
goto out;
}
-
- fill_hdr(sctns);
- fill_stsi(sctns);
- fill_diag(sctns);
-
+ if (copy_to_user(buffer, info, PAGE_SIZE))
+ r = -EFAULT;
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] = cc ? 4 : 0;
- kvm_s390_set_psw_cc(vcpu, cc);
+ 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 <asm/kvm_host.h>
#include <asm/asm-offsets.h>
#include <asm/irq.h>
+#include <asm/sysinfo.h>
#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, &reg1, &reg2);
+ 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);

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