From: Janosch Frank <frankja@linux.ibm.com>
Subject: KVM: s390: Refactor host cmma and pfmfi interpretation controls
Patch-mainline: v4.17-rc1
Git-commit: c9f0a2b87f9e95197c2f81920a82bcef6ad3db99
References: FATE#326372, LTC#169184, bsc#1113484
Summary: kernel: Introduce huge page KVM backing support
Description: This adds the KVM support for libhugetlbfs backings of
s390 KVM guests.
Upstream-Description:
KVM: s390: Refactor host cmma and pfmfi interpretation controls
use_cmma in kvm_arch means that the KVM hypervisor is allowed to use
cmma, whereas use_cmma in the mm context means cmm has been used before.
Let's rename the context one to uses_cmm, as the vm does use
collaborative memory management but the host uses the cmm assist
(interpretation facility).
Also let's introduce use_pfmfi, so we can remove the pfmfi disablement
when we activate cmma and rather not activate it in the first place.
Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Message-Id: <1518779775-256056-2-git-send-email-frankja@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
arch/s390/include/asm/kvm_host.h | 1 +
arch/s390/include/asm/mmu.h | 4 ++--
arch/s390/include/asm/mmu_context.h | 2 +-
arch/s390/kvm/kvm-s390.c | 23 ++++++++++++-----------
arch/s390/kvm/priv.c | 4 ++--
5 files changed, 18 insertions(+), 16 deletions(-)
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -743,6 +743,7 @@ struct kvm_arch{
int css_support;
int use_irqchip;
int use_cmma;
+ int use_pfmfi;
int user_cpu_state_ctrl;
int user_sigp;
int user_stsi;
--- a/arch/s390/include/asm/mmu.h
+++ b/arch/s390/include/asm/mmu.h
@@ -23,8 +23,8 @@ typedef struct {
unsigned int has_pgste:1;
/* The mmu context uses storage keys. */
unsigned int use_skey:1;
- /* The mmu context uses CMMA. */
- unsigned int use_cmma:1;
+ /* The mmu context uses CMM. */
+ unsigned int uses_cmm:1;
} mm_context_t;
#define INIT_MM_CONTEXT(name) \
--- a/arch/s390/include/asm/mmu_context.h
+++ b/arch/s390/include/asm/mmu_context.h
@@ -32,7 +32,7 @@ static inline int init_new_context(struc
(current->mm && current->mm->context.alloc_pgste);
mm->context.has_pgste = 0;
mm->context.use_skey = 0;
- mm->context.use_cmma = 0;
+ mm->context.uses_cmm = 0;
#endif
switch (mm->context.asce_limit) {
case 1UL << 42:
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -698,6 +698,8 @@ static int kvm_s390_set_mem_control(stru
mutex_lock(&kvm->lock);
if (!kvm->created_vcpus) {
kvm->arch.use_cmma = 1;
+ /* Not compatible with cmma. */
+ kvm->arch.use_pfmfi = 0;
ret = 0;
}
mutex_unlock(&kvm->lock);
@@ -1590,7 +1592,7 @@ static int kvm_s390_get_cmma_bits(struct
return -EINVAL;
/* CMMA is disabled or was not used, or the buffer has length zero */
bufsize = min(args->count, KVM_S390_CMMA_SIZE_MAX);
- if (!bufsize || !kvm->mm->context.use_cmma) {
+ if (!bufsize || !kvm->mm->context.uses_cmm) {
memset(args, 0, sizeof(*args));
return 0;
}
@@ -1667,7 +1669,7 @@ static int kvm_s390_get_cmma_bits(struct
/*
* This function sets the CMMA attributes for the given pages. If the input
* buffer has zero length, no action is taken, otherwise the attributes are
- * set and the mm->context.use_cmma flag is set.
+ * set and the mm->context.uses_cmm flag is set.
*/
static int kvm_s390_set_cmma_bits(struct kvm *kvm,
const struct kvm_s390_cmma_log *args)
@@ -1717,9 +1719,9 @@ static int kvm_s390_set_cmma_bits(struct
srcu_read_unlock(&kvm->srcu, srcu_idx);
up_read(&kvm->mm->mmap_sem);
- if (!kvm->mm->context.use_cmma) {
+ if (!kvm->mm->context.uses_cmm) {
down_write(&kvm->mm->mmap_sem);
- kvm->mm->context.use_cmma = 1;
+ kvm->mm->context.uses_cmm = 1;
up_write(&kvm->mm->mmap_sem);
}
out:
@@ -2029,6 +2031,7 @@ int kvm_arch_init_vm(struct kvm *kvm, un
kvm->arch.css_support = 0;
kvm->arch.use_irqchip = 0;
+ kvm->arch.use_pfmfi = sclp.has_pfmfi;
kvm->arch.epoch = 0;
spin_lock_init(&kvm->arch.start_stop_lock);
@@ -2454,8 +2457,6 @@ int kvm_s390_vcpu_setup_cmma(struct kvm_
vcpu->arch.sie_block->cbrlo = get_zeroed_page(GFP_KERNEL);
if (!vcpu->arch.sie_block->cbrlo)
return -ENOMEM;
-
- vcpu->arch.sie_block->ecb2 &= ~ECB2_PFMFI;
return 0;
}
@@ -2491,7 +2492,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu
if (test_kvm_facility(vcpu->kvm, 73))
vcpu->arch.sie_block->ecb |= ECB_TE;
- if (test_kvm_facility(vcpu->kvm, 8) && sclp.has_pfmfi)
+ if (test_kvm_facility(vcpu->kvm, 8) && vcpu->kvm->arch.use_pfmfi)
vcpu->arch.sie_block->ecb2 |= ECB2_PFMFI;
if (test_kvm_facility(vcpu->kvm, 130))
vcpu->arch.sie_block->ecb2 |= ECB2_IEP;
@@ -2978,7 +2979,7 @@ retry:
if (kvm_check_request(KVM_REQ_START_MIGRATION, vcpu)) {
/*
- * Disable CMMA virtualization; we will emulate the ESSA
+ * Disable CMM virtualization; we will emulate the ESSA
* instruction manually, in order to provide additional
* functionalities needed for live migration.
*/
@@ -2988,11 +2989,11 @@ retry:
if (kvm_check_request(KVM_REQ_STOP_MIGRATION, vcpu)) {
/*
- * Re-enable CMMA virtualization if CMMA is available and
- * was used.
+ * Re-enable CMM virtualization if CMMA is available and
+ * CMM has been used.
*/
if ((vcpu->kvm->arch.use_cmma) &&
- (vcpu->kvm->mm->context.use_cmma))
+ (vcpu->kvm->mm->context.uses_cmm))
vcpu->arch.sie_block->ecb2 |= ECB2_CMMA;
goto retry;
}
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -1073,9 +1073,9 @@ static int handle_essa(struct kvm_vcpu *
* value really needs to be written to; if the value is
* already correct, we do nothing and avoid the lock.
*/
- if (vcpu->kvm->mm->context.use_cmma == 0) {
+ if (vcpu->kvm->mm->context.uses_cmm == 0) {
down_write(&vcpu->kvm->mm->mmap_sem);
- vcpu->kvm->mm->context.use_cmma = 1;
+ vcpu->kvm->mm->context.uses_cmm = 1;
up_write(&vcpu->kvm->mm->mmap_sem);
}
/*