From 7420ff03f2ac2c4511957776d9f67ddf2973145b Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Mon, 24 Oct 2011 11:47:52 +0200 Subject: [PATCH] [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 Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/kvm_host.h | 1 + arch/s390/include/asm/pgtable.h | 1 + arch/s390/kvm/diag.c | 32 ++++++++++++++++++++- arch/s390/kvm/kvm-s390.c | 1 + arch/s390/mm/pgtable.c | 49 +++++++++++++++++++++++++++++++- 5 files changed, 82 insertions(+), 2 deletions(-) diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 00ff00dfb24c..46c0bdaf4792 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -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; }; diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index bc5f520f6f87..34ede0ea85a9 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -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 diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c index 9e4c84187cf5..87cedd61be04 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 #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: diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index dc2b580e27bc..189d6bdcac08 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -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 } }; diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 441d34445d0e..301c84d3b542 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 */ @@ -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; -- 2.39.5