From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Reviewed-by: Thomas Huth <thuth@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
arch/s390/include/asm/kvm_host.h | 12 ++++-
arch/s390/kvm/gaccess.c | 109 +++++++++++++++++++++++++++++++++++++++
arch/s390/kvm/gaccess.h | 2 +
arch/s390/kvm/kvm-s390.c | 2 +
arch/s390/kvm/priv.c | 18 +++++++
5 files changed, 142 insertions(+), 1 deletion(-)
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index c290d44..f1ed7bd 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -39,9 +39,17 @@ struct sca_entry {
__u64 reserved2[2];
} __attribute__((packed));
+union ipte_control {
+ unsigned long val;
+ struct {
+ unsigned long k : 1;
+ unsigned long kh : 31;
+ unsigned long kg : 32;
+ };
+};
struct sca_block {
- __u64 ipte_control;
+ union ipte_control ipte_control;
__u64 reserved[5];
__u64 mcn;
__u64 reserved2;
@@ -167,6 +175,7 @@ struct kvm_vcpu_stat {
u32 instruction_stpx;
u32 instruction_stap;
u32 instruction_storage_key;
+ u32 instruction_ipte_interlock;
u32 instruction_stsch;
u32 instruction_chsc;
u32 instruction_stsi;
@@ -336,6 +345,7 @@ struct kvm_arch{
int use_irqchip;
int use_cmma;
struct s390_io_adapter *adapters[MAX_S390_IO_ADAPTERS];
+ wait_queue_head_t ipte_wq;
};
#define KVM_HVA_ERR_BAD (-1UL)
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 916e1ee..691fdb7 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -207,6 +207,107 @@ union raddress {
unsigned long pfra : 52; /* Page-Frame Real Address */
};
+static int ipte_lock_count;
+static DEFINE_MUTEX(ipte_mutex);
+
+int ipte_lock_held(struct kvm_vcpu *vcpu)
+{
+ union ipte_control *ic = &vcpu->kvm->arch.sca->ipte_control;
+
+ if (vcpu->arch.sie_block->eca & 1)
+ return ic->kh != 0;
+ return ipte_lock_count != 0;
+}
+
+static void ipte_lock_simple(struct kvm_vcpu *vcpu)
+{
+ union ipte_control old, new, *ic;
+
+ mutex_lock(&ipte_mutex);
+ ipte_lock_count++;
+ if (ipte_lock_count > 1)
+ goto out;
+ ic = &vcpu->kvm->arch.sca->ipte_control;
+ do {
+ old = ACCESS_ONCE(*ic);
+ while (old.k) {
+ cond_resched();
+ old = ACCESS_ONCE(*ic);
+ }
+ new = old;
+ new.k = 1;
+ } while (cmpxchg(&ic->val, old.val, new.val) != old.val);
+out:
+ mutex_unlock(&ipte_mutex);
+}
+
+static void ipte_unlock_simple(struct kvm_vcpu *vcpu)
+{
+ union ipte_control old, new, *ic;
+
+ mutex_lock(&ipte_mutex);
+ ipte_lock_count--;
+ if (ipte_lock_count)
+ goto out;
+ ic = &vcpu->kvm->arch.sca->ipte_control;
+ do {
+ new = old = ACCESS_ONCE(*ic);
+ new.k = 0;
+ } while (cmpxchg(&ic->val, old.val, new.val) != old.val);
+ if (!ipte_lock_count)
+ wake_up(&vcpu->kvm->arch.ipte_wq);
+out:
+ mutex_unlock(&ipte_mutex);
+}
+
+static void ipte_lock_siif(struct kvm_vcpu *vcpu)
+{
+ union ipte_control old, new, *ic;
+
+ ic = &vcpu->kvm->arch.sca->ipte_control;
+ do {
+ old = ACCESS_ONCE(*ic);
+ while (old.kg) {
+ cond_resched();
+ old = ACCESS_ONCE(*ic);
+ }
+ new = old;
+ new.k = 1;
+ new.kh++;
+ } while (cmpxchg(&ic->val, old.val, new.val) != old.val);
+}
+
+static void ipte_unlock_siif(struct kvm_vcpu *vcpu)
+{
+ union ipte_control old, new, *ic;
+
+ ic = &vcpu->kvm->arch.sca->ipte_control;
+ do {
+ new = old = ACCESS_ONCE(*ic);
+ new.kh--;
+ if (!new.kh)
+ new.k = 0;
+ } while (cmpxchg(&ic->val, old.val, new.val) != old.val);
+ if (!new.kh)
+ wake_up(&vcpu->kvm->arch.ipte_wq);
+}
+
+static void ipte_lock(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->arch.sie_block->eca & 1)
+ ipte_lock_siif(vcpu);
+ else
+ ipte_lock_simple(vcpu);
+}
+
+static void ipte_unlock(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->arch.sie_block->eca & 1)
+ ipte_unlock_siif(vcpu);
+ else
+ ipte_unlock_simple(vcpu);
+}
+
static unsigned long get_vcpu_asce(struct kvm_vcpu *vcpu)
{
switch (psw_bits(vcpu->arch.sie_block->gpsw).as) {
@@ -485,6 +586,8 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, void *data,
unsigned long _len, nr_pages, gpa, idx;
unsigned long pages_array[2];
unsigned long *pages;
+ int need_ipte_lock;
+ union asce asce;
int rc;
if (!len)
@@ -498,6 +601,10 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, void *data,
pages = vmalloc(nr_pages * sizeof(unsigned long));
if (!pages)
return -ENOMEM;
+ asce.val = get_vcpu_asce(vcpu);
+ need_ipte_lock = psw_bits(*psw).t && !asce.r;
+ if (need_ipte_lock)
+ ipte_lock(vcpu);
rc = guest_page_range(vcpu, ga, pages, nr_pages, write);
for (idx = 0; idx < nr_pages && !rc; idx++) {
gpa = *(pages + idx) + (ga & ~PAGE_MASK);
@@ -510,6 +617,8 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, void *data,
ga += _len;
data += _len;
}
+ if (need_ipte_lock)
+ ipte_unlock(vcpu);
if (nr_pages > ARRAY_SIZE(pages_array))
vfree(pages);
return rc;
diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/gaccess.h
index 21ee62c..f46e764 100644
--- a/arch/s390/kvm/gaccess.h
+++ b/arch/s390/kvm/gaccess.h
@@ -397,4 +397,6 @@ int read_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
return access_guest_real(vcpu, gra, data, len, 0);
}
+int ipte_lock_held(struct kvm_vcpu *vcpu);
+
#endif /* __KVM_S390_GACCESS_H */
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 927ba73..e1dfe24 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -67,6 +67,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "instruction_stpx", VCPU_STAT(instruction_stpx) },
{ "instruction_stap", VCPU_STAT(instruction_stap) },
{ "instruction_storage_key", VCPU_STAT(instruction_storage_key) },
+ { "instruction_ipte_interlock", VCPU_STAT(instruction_ipte_interlock) },
{ "instruction_stsch", VCPU_STAT(instruction_stsch) },
{ "instruction_chsc", VCPU_STAT(instruction_chsc) },
{ "instruction_essa", VCPU_STAT(instruction_essa) },
@@ -437,6 +438,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
spin_lock_init(&kvm->arch.float_int.lock);
INIT_LIST_HEAD(&kvm->arch.float_int.list);
+ init_waitqueue_head(&kvm->arch.ipte_wq);
debug_register_view(kvm->arch.dbf, &debug_sprintf_view);
VM_EVENT(kvm, 3, "%s", "vm created");
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 9a04d74..4792f1d 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -173,6 +173,19 @@ static int handle_skey(struct kvm_vcpu *vcpu)
return 0;
}
+static int handle_ipte_interlock(struct kvm_vcpu *vcpu)
+{
+ psw_t *psw = &vcpu->arch.sie_block->gpsw;
+
+ vcpu->stat.instruction_ipte_interlock++;
+ if (psw_bits(*psw).p)
+ return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
+ wait_event(vcpu->kvm->arch.ipte_wq, !ipte_lock_held(vcpu));
+ psw->addr = __rewind_psw(*psw, 4);
+ VCPU_EVENT(vcpu, 4, "%s", "retrying ipte interlock operation");
+ return 0;
+}
+
static int handle_test_block(struct kvm_vcpu *vcpu)
{
unsigned long hva;
@@ -509,6 +522,7 @@ static const intercept_handler_t b2_handlers[256] = {
[0x10] = handle_set_prefix,
[0x11] = handle_store_prefix,
[0x12] = handle_store_cpu_address,
+ [0x21] = handle_ipte_interlock,
[0x29] = handle_skey,
[0x2a] = handle_skey,
[0x2b] = handle_skey,
@@ -526,6 +540,7 @@ static const intercept_handler_t b2_handlers[256] = {
[0x3a] = handle_io_inst,
[0x3b] = handle_io_inst,
[0x3c] = handle_io_inst,
+ [0x50] = handle_ipte_interlock,
[0x5f] = handle_io_inst,
[0x74] = handle_io_inst,
[0x76] = handle_io_inst,
@@ -686,7 +701,10 @@ static int handle_essa(struct kvm_vcpu *vcpu)
}
static const intercept_handler_t b9_handlers[256] = {
+ [0x8a] = handle_ipte_interlock,
[0x8d] = handle_epsw,
+ [0x8e] = handle_ipte_interlock,
+ [0x8f] = handle_ipte_interlock,
[0xab] = handle_essa,
[0xaf] = handle_pfmf,
};
--
1.8.4.2
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