From: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
Pin the guest pages when they are first accessed, instead of all at
the same time when starting the guest.
Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
---
arch/s390/include/asm/gmap.h | 1 +
arch/s390/include/asm/uv.h | 6 +++++
arch/s390/kernel/uv.c | 20 ++++++++++++++
arch/s390/kvm/kvm-s390.c | 2 ++
arch/s390/kvm/pv.c | 51 ++++++++++++++++++++++++++++++------
5 files changed, 72 insertions(+), 8 deletions(-)
diff --git a/arch/s390/include/asm/gmap.h b/arch/s390/include/asm/gmap.h
index 99b3eedda26e..483f64427c0e 100644
--- a/arch/s390/include/asm/gmap.h
+++ b/arch/s390/include/asm/gmap.h
@@ -63,6 +63,7 @@ struct gmap {
struct gmap *parent;
unsigned long orig_asce;
unsigned long se_handle;
+ struct page **pinned_pages;
int edat_level;
bool removed;
bool initialized;
diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
index 99cdd2034503..9ce9363aee1c 100644
--- a/arch/s390/include/asm/uv.h
+++ b/arch/s390/include/asm/uv.h
@@ -298,6 +298,7 @@ static inline int uv_convert_from_secure(unsigned long paddr)
return -EINVAL;
}
+int kvm_s390_pv_pin_page(struct gmap *gmap, unsigned long gpa);
/*
* Requests the Ultravisor to make a page accessible to a guest
* (import). If it's brought in the first time, it will be cleared. If
@@ -317,6 +318,11 @@ static inline int uv_convert_to_secure(struct gmap *gmap, unsigned long gaddr)
.gaddr = gaddr
};
+ down_read(&gmap->mm->mmap_sem);
+ cc = kvm_s390_pv_pin_page(gmap, gaddr);
+ up_read(&gmap->mm->mmap_sem);
+ if (cc)
+ return cc;
cc = uv_call(0, (u64)&uvcb);
if (!cc)
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index f7778493e829..36554402b5c6 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -98,4 +98,24 @@ void adjust_to_uv_max(unsigned long *vmax)
if (prot_virt_host && *vmax > uv_info.max_sec_stor_addr)
*vmax = uv_info.max_sec_stor_addr;
}
+
+int kvm_s390_pv_pin_page(struct gmap *gmap, unsigned long gpa)
+{
+ unsigned long hva, gfn = gpa / PAGE_SIZE;
+ int rc;
+
+ if (!gmap->pinned_pages)
+ return -EINVAL;
+ hva = __gmap_translate(gmap, gpa);
+ if (IS_ERR_VALUE(hva))
+ return -EFAULT;
+ if (gmap->pinned_pages[gfn])
+ return -EEXIST;
+ rc = get_user_pages_fast(hva, 1, FOLL_WRITE, gmap->pinned_pages + gfn);
+ if (rc < 0)
+ return rc;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_s390_pv_pin_page);
+
#endif
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index d1ba12f857e7..490fde080107 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2196,6 +2196,7 @@ static int kvm_s390_handle_pv(struct kvm *kvm, struct kvm_pv_cmd *cmd)
/* All VCPUs have to be destroyed before this call. */
mutex_lock(&kvm->lock);
kvm_s390_vcpu_block_all(kvm);
+ kvm_s390_pv_unpin(kvm);
r = kvm_s390_pv_destroy_vm(kvm);
if (!r)
kvm_s390_pv_dealloc_vm(kvm);
@@ -2680,6 +2681,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
kvm_s390_gisa_destroy(kvm);
if (IS_ENABLED(CONFIG_KVM_S390_PROTECTED_VIRTUALIZATION_HOST) &&
kvm_s390_pv_is_protected(kvm)) {
+ kvm_s390_pv_unpin(kvm);
kvm_s390_pv_destroy_vm(kvm);
kvm_s390_pv_dealloc_vm(kvm);
}
diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
index 80aecd5bea9e..383e660e2221 100644
--- a/arch/s390/kvm/pv.c
+++ b/arch/s390/kvm/pv.c
@@ -15,8 +15,35 @@
#include <asm/mman.h>
#include "kvm-s390.h"
+static void unpin_destroy(struct page **pages, int nr)
+{
+ int i;
+ struct page *page;
+ u8 *val;
+
+ for (i = 0; i < nr; i++) {
+ page = pages[i];
+ if (!page) /* page was never used */
+ continue;
+ val = (void *)page_to_phys(page);
+ READ_ONCE(*val);
+ put_page(page);
+ }
+}
+
+void kvm_s390_pv_unpin(struct kvm *kvm)
+{
+ unsigned long npages = kvm->arch.pv.guest_len / PAGE_SIZE;
+
+ mutex_lock(&kvm->slots_lock);
+ unpin_destroy(kvm->arch.gmap->pinned_pages, npages);
+ mutex_unlock(&kvm->slots_lock);
+}
+
void kvm_s390_pv_dealloc_vm(struct kvm *kvm)
{
+ vfree(kvm->arch.gmap->pinned_pages);
+ kvm->arch.gmap->pinned_pages = NULL;
vfree(kvm->arch.pv.stor_var);
free_pages(kvm->arch.pv.stor_base,
get_order(uv_info.guest_base_stor_len));
@@ -28,7 +55,6 @@ int kvm_s390_pv_alloc_vm(struct kvm *kvm)
unsigned long base = uv_info.guest_base_stor_len;
unsigned long virt = uv_info.guest_virt_var_stor_len;
unsigned long npages = 0, vlen = 0;
- struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
kvm->arch.pv.stor_var = NULL;
@@ -43,22 +69,26 @@ int kvm_s390_pv_alloc_vm(struct kvm *kvm)
* Slots are sorted by GFN
*/
mutex_lock(&kvm->slots_lock);
- slots = kvm_memslots(kvm);
- memslot = slots->memslots;
+ memslot = kvm_memslots(kvm)->memslots;
npages = memslot->base_gfn + memslot->npages;
-
mutex_unlock(&kvm->slots_lock);
+
+ kvm->arch.gmap->pinned_pages = vzalloc(npages * sizeof(struct page *));
+ if (!kvm->arch.gmap->pinned_pages)
+ goto out_err;
kvm->arch.pv.guest_len = npages * PAGE_SIZE;
/* Allocate variable storage */
vlen = ALIGN(virt * ((npages * PAGE_SIZE) / HPAGE_SIZE), PAGE_SIZE);
vlen += uv_info.guest_virt_base_stor_len;
kvm->arch.pv.stor_var = vzalloc(vlen);
- if (!kvm->arch.pv.stor_var) {
- kvm_s390_pv_dealloc_vm(kvm);
- return -ENOMEM;
- }
+ if (!kvm->arch.pv.stor_var)
+ goto out_err;
return 0;
+
+out_err:
+ kvm_s390_pv_dealloc_vm(kvm);
+ return -ENOMEM;
}
int kvm_s390_pv_destroy_vm(struct kvm *kvm)
@@ -216,6 +246,11 @@ int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
for (i = 0; i < size / PAGE_SIZE; i++) {
uvcb.gaddr = addr + i * PAGE_SIZE;
uvcb.tweak[1] = i * PAGE_SIZE;
+ down_read(&kvm->mm->mmap_sem);
+ rc = kvm_s390_pv_pin_page(kvm->arch.gmap, uvcb.gaddr);
+ up_read(&kvm->mm->mmap_sem);
+ if (rc && (rc != -EEXIST))
+ break;
retry:
rc = uv_call(0, (u64)&uvcb);
if (!rc)
--
2.20.1
