[S390] kvm: Handle diagnose 0x10 (release pages)
Linux on System z uses a ballooner based on diagnose 0x10. (aka as
collaborative memory management). This patch implements diagnose
0x10 on the guest address space.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 00ff00d..46c0bda 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -143,6 +143,7 @@
u32 instruction_sigp_arch;
u32 instruction_sigp_prefix;
u32 instruction_sigp_restart;
+ u32 diagnose_10;
u32 diagnose_44;
};
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index bc5f520..34ede0e 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -698,6 +698,7 @@
int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len);
unsigned long __gmap_fault(unsigned long address, struct gmap *);
unsigned long gmap_fault(unsigned long address, struct gmap *);
+void gmap_discard(unsigned long from, unsigned long to, struct gmap *);
/*
* Certain architectures need to do special things when PTEs
diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
index 9e4c841..87cedd6 100644
--- a/arch/s390/kvm/diag.c
+++ b/arch/s390/kvm/diag.c
@@ -1,7 +1,7 @@
/*
* diag.c - handling diagnose instructions
*
- * Copyright IBM Corp. 2008
+ * Copyright IBM Corp. 2008,2011
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (version 2 only)
@@ -15,6 +15,34 @@
#include <linux/kvm_host.h>
#include "kvm-s390.h"
+static int diag_release_pages(struct kvm_vcpu *vcpu)
+{
+ unsigned long start, end;
+ unsigned long prefix = vcpu->arch.sie_block->prefix;
+
+ start = vcpu->arch.guest_gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
+ end = vcpu->arch.guest_gprs[vcpu->arch.sie_block->ipa & 0xf] + 4096;
+
+ if (start & ~PAGE_MASK || end & ~PAGE_MASK || start > end
+ || start < 2 * PAGE_SIZE)
+ return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+
+ VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
+ vcpu->stat.diagnose_10++;
+
+ /* we checked for start > end above */
+ if (end < prefix || start >= prefix + 2 * PAGE_SIZE) {
+ gmap_discard(start, end, vcpu->arch.gmap);
+ } else {
+ if (start < prefix)
+ gmap_discard(start, prefix, vcpu->arch.gmap);
+ if (end >= prefix)
+ gmap_discard(prefix + 2 * PAGE_SIZE,
+ end, vcpu->arch.gmap);
+ }
+ return 0;
+}
+
static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
{
VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
@@ -57,6 +85,8 @@
int code = (vcpu->arch.sie_block->ipb & 0xfff0000) >> 16;
switch (code) {
+ case 0x10:
+ return diag_release_pages(vcpu);
case 0x44:
return __diag_time_slice_end(vcpu);
case 0x308:
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index dc2b580..189d6bd 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -69,6 +69,7 @@
{ "instruction_sigp_set_arch", VCPU_STAT(instruction_sigp_arch) },
{ "instruction_sigp_set_prefix", VCPU_STAT(instruction_sigp_prefix) },
{ "instruction_sigp_restart", VCPU_STAT(instruction_sigp_restart) },
+ { "diagnose_10", VCPU_STAT(diagnose_10) },
{ "diagnose_44", VCPU_STAT(diagnose_44) },
{ NULL }
};
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 441d344..301c84d 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -1,5 +1,5 @@
/*
- * Copyright IBM Corp. 2007,2009
+ * Copyright IBM Corp. 2007,2011
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
*/
@@ -478,6 +478,53 @@
}
EXPORT_SYMBOL_GPL(gmap_fault);
+void gmap_discard(unsigned long from, unsigned long to, struct gmap *gmap)
+{
+
+ unsigned long *table, address, size;
+ struct vm_area_struct *vma;
+ struct gmap_pgtable *mp;
+ struct page *page;
+
+ down_read(&gmap->mm->mmap_sem);
+ address = from;
+ while (address < to) {
+ /* Walk the gmap address space page table */
+ table = gmap->table + ((address >> 53) & 0x7ff);
+ if (unlikely(*table & _REGION_ENTRY_INV)) {
+ address = (address + PMD_SIZE) & PMD_MASK;
+ continue;
+ }
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ table = table + ((address >> 42) & 0x7ff);
+ if (unlikely(*table & _REGION_ENTRY_INV)) {
+ address = (address + PMD_SIZE) & PMD_MASK;
+ continue;
+ }
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ table = table + ((address >> 31) & 0x7ff);
+ if (unlikely(*table & _REGION_ENTRY_INV)) {
+ address = (address + PMD_SIZE) & PMD_MASK;
+ continue;
+ }
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ table = table + ((address >> 20) & 0x7ff);
+ if (unlikely(*table & _SEGMENT_ENTRY_INV)) {
+ address = (address + PMD_SIZE) & PMD_MASK;
+ continue;
+ }
+ page = pfn_to_page(*table >> PAGE_SHIFT);
+ mp = (struct gmap_pgtable *) page->index;
+ vma = find_vma(gmap->mm, mp->vmaddr);
+ size = min(to - address, PMD_SIZE - (address & ~PMD_MASK));
+ zap_page_range(vma, mp->vmaddr | (address & ~PMD_MASK),
+ size, NULL);
+ address = (address + PMD_SIZE) & PMD_MASK;
+ }
+ up_read(&gmap->mm->mmap_sem);
+}
+EXPORT_SYMBOL_GPL(gmap_discard);
+
void gmap_unmap_notifier(struct mm_struct *mm, unsigned long *table)
{
struct gmap_rmap *rmap, *next;