[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>
This commit is contained in:
Christian Borntraeger 2011-10-30 15:17:03 +01:00 committed by Martin Schwidefsky
parent 499069e1a4
commit 388186bc92
5 changed files with 82 additions and 2 deletions

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@ -143,6 +143,7 @@ struct kvm_vcpu_stat {
u32 instruction_sigp_arch;
u32 instruction_sigp_prefix;
u32 instruction_sigp_restart;
u32 diagnose_10;
u32 diagnose_44;
};

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@ -698,6 +698,7 @@ int gmap_map_segment(struct gmap *gmap, unsigned long from,
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

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@ -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 kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
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:

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@ -69,6 +69,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "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 }
};

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@ -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 @@ unsigned long gmap_fault(unsigned long address, struct gmap *gmap)
}
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;