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Commit 388186bc authored by Christian Borntraeger's avatar Christian Borntraeger Committed by Martin Schwidefsky
Browse files

[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: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 499069e1

arch/s390/include/asm/kvm_host.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

};

arch/s390/include/asm/pgtable.h

+1 −0
Original line number Diff line number Diff line
@@ -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

arch/s390/kvm/diag.c

+31 −1
Original line number Diff line number Diff line 
/*

 * 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:

arch/s390/kvm/kvm-s390.c

+1 −0
Original line number Diff line number Diff line
@@ -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 }

};

arch/s390/mm/pgtable.c

+48 −1
Original line number Diff line number Diff line 
/*

 *    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;