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| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2014-09-03 21:23:13 +0200 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2014-09-10 12:19:42 +0200 |
| commit | f7a960affc6e5a33e8c7fcef065affc4f0461041 (patch) | |
| tree | 4ffa230638dd30ef0f82201b3c3a6945bc4f35fd /arch | |
| parent | 6b331952f1bc2df61c98954e25578629c439e417 (diff) | |
| download | linux-f7a960affc6e5a33e8c7fcef065affc4f0461041.tar.bz2 | |
KVM: s390/cmm: Fix prefix handling for diag 10 balloon
The old handling of prefix pages was broken in the diag10 ballooner.
We now rely on gmap_discard to check for start > end and do a
slow path if the prefix swap pages are affected:
1. discard the pages from start to prefix
2. discard the absolute 0 pages
3. discard the pages after prefix swap to end
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/s390/kvm/diag.c | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c index b374b6cb7785..9254afff250c 100644 --- a/arch/s390/kvm/diag.c +++ b/arch/s390/kvm/diag.c @@ -28,22 +28,32 @@ static int diag_release_pages(struct kvm_vcpu *vcpu) start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4]; end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + 4096; - if (start & ~PAGE_MASK || end & ~PAGE_MASK || start > end + 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) { + /* + * We checked for start >= end above, so lets check for the + * fast path (no prefix swap page involved) + */ + if (end <= prefix || start >= prefix + 2 * PAGE_SIZE) { gmap_discard(vcpu->arch.gmap, start, end); } else { - if (start < prefix) - gmap_discard(vcpu->arch.gmap, start, prefix); - if (end >= prefix) - gmap_discard(vcpu->arch.gmap, - prefix + 2 * PAGE_SIZE, end); + /* + * This is slow path. gmap_discard will check for start + * so lets split this into before prefix, prefix, after + * prefix and let gmap_discard make some of these calls + * NOPs. + */ + gmap_discard(vcpu->arch.gmap, start, prefix); + if (start <= prefix) + gmap_discard(vcpu->arch.gmap, 0, 4096); + if (end > prefix + 4096) + gmap_discard(vcpu->arch.gmap, 4096, 8192); + gmap_discard(vcpu->arch.gmap, prefix + 2 * PAGE_SIZE, end); } return 0; } |