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Commit 628eb9b8 authored by Christian Ehrhardt's avatar Christian Ehrhardt Committed by Avi Kivity
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KVM: s390: streamline memslot handling 



This patch relocates the variables kvm-s390 uses to track guest mem addr/size.
As discussed dropping the variables at struct kvm_arch level allows to use the
common vcpu->request based mechanism to reload guest memory if e.g. changes
via set_memory_region.

The kick mechanism introduced in this series is used to ensure running vcpus
leave guest state to catch the update.

Signed-off-by: default avatarChristian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent b1d16c49

arch/s390/include/asm/kvm_host.h

+1 −3
Original line number Diff line number Diff line 
/*

 * asm-s390/kvm_host.h - definition for kernel virtual machines on s390

 *

 * Copyright IBM Corp. 2008

 * Copyright IBM Corp. 2008,2009

 *

 * 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)
@@ -228,8 +228,6 @@ struct kvm_vm_stat { 
};



struct kvm_arch{

	unsigned long guest_origin;

	unsigned long guest_memsize;

	struct sca_block *sca;

	debug_info_t *dbf;

	struct kvm_s390_float_interrupt float_int;

arch/s390/kvm/gaccess.h

+12 −11
Original line number Diff line number Diff line 
/*

 * gaccess.h -  access guest memory

 *

 * Copyright IBM Corp. 2008

 * Copyright IBM Corp. 2008,2009

 *

 * 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)
@@ -16,13 +16,14 @@ 
#include <linux/compiler.h>

#include <linux/kvm_host.h>

#include <asm/uaccess.h>

#include "kvm-s390.h"



static inline void __user *__guestaddr_to_user(struct kvm_vcpu *vcpu,

					       unsigned long guestaddr)

{

	unsigned long prefix  = vcpu->arch.sie_block->prefix;

	unsigned long origin  = vcpu->kvm->arch.guest_origin;

	unsigned long memsize = vcpu->kvm->arch.guest_memsize;

	unsigned long origin  = vcpu->arch.sie_block->gmsor;

	unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);



	if (guestaddr < 2 * PAGE_SIZE)

		guestaddr += prefix;
@@ -158,8 +159,8 @@ static inline int copy_to_guest(struct kvm_vcpu *vcpu, unsigned long guestdest, 
				const void *from, unsigned long n)

{

	unsigned long prefix  = vcpu->arch.sie_block->prefix;

	unsigned long origin  = vcpu->kvm->arch.guest_origin;

	unsigned long memsize = vcpu->kvm->arch.guest_memsize;

	unsigned long origin  = vcpu->arch.sie_block->gmsor;

	unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);



	if ((guestdest < 2 * PAGE_SIZE) && (guestdest + n > 2 * PAGE_SIZE))

		goto slowpath;
@@ -209,8 +210,8 @@ static inline int copy_from_guest(struct kvm_vcpu *vcpu, void *to, 
				  unsigned long guestsrc, unsigned long n)

{

	unsigned long prefix  = vcpu->arch.sie_block->prefix;

	unsigned long origin  = vcpu->kvm->arch.guest_origin;

	unsigned long memsize = vcpu->kvm->arch.guest_memsize;

	unsigned long origin  = vcpu->arch.sie_block->gmsor;

	unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);



	if ((guestsrc < 2 * PAGE_SIZE) && (guestsrc + n > 2 * PAGE_SIZE))

		goto slowpath;
@@ -244,8 +245,8 @@ static inline int copy_to_guest_absolute(struct kvm_vcpu *vcpu, 
					 unsigned long guestdest,

					 const void *from, unsigned long n)

{

	unsigned long origin  = vcpu->kvm->arch.guest_origin;

	unsigned long memsize = vcpu->kvm->arch.guest_memsize;

	unsigned long origin  = vcpu->arch.sie_block->gmsor;

	unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);



	if (guestdest + n > memsize)

		return -EFAULT;
@@ -262,8 +263,8 @@ static inline int copy_from_guest_absolute(struct kvm_vcpu *vcpu, void *to, 
					   unsigned long guestsrc,

					   unsigned long n)

{

	unsigned long origin  = vcpu->kvm->arch.guest_origin;

	unsigned long memsize = vcpu->kvm->arch.guest_memsize;

	unsigned long origin  = vcpu->arch.sie_block->gmsor;

	unsigned long memsize = kvm_s390_vcpu_get_memsize(vcpu);



	if (guestsrc + n > memsize)

		return -EFAULT;

arch/s390/kvm/intercept.c

+3 −3
Original line number Diff line number Diff line 
/*

 * intercept.c - in-kernel handling for sie intercepts

 *

 * Copyright IBM Corp. 2008

 * Copyright IBM Corp. 2008,2009

 *

 * 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)
@@ -164,9 +164,9 @@ static int handle_validity(struct kvm_vcpu *vcpu) 


	vcpu->stat.exit_validity++;

	if ((viwhy == 0x37) && (vcpu->arch.sie_block->prefix

		<= vcpu->kvm->arch.guest_memsize - 2*PAGE_SIZE)){

		<= kvm_s390_vcpu_get_memsize(vcpu) - 2*PAGE_SIZE)) {

		rc = fault_in_pages_writeable((char __user *)

			 vcpu->kvm->arch.guest_origin +

			 vcpu->arch.sie_block->gmsor +

			 vcpu->arch.sie_block->prefix,

			 2*PAGE_SIZE);

		if (rc)

arch/s390/kvm/kvm-s390.c

+16 −34
Original line number Diff line number Diff line 
/*

 * s390host.c --  hosting zSeries kernel virtual machines

 *

 * Copyright IBM Corp. 2008

 * Copyright IBM Corp. 2008,2009

 *

 * 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)
@@ -10,6 +10,7 @@ 
 *    Author(s): Carsten Otte <cotte@de.ibm.com>

 *               Christian Borntraeger <borntraeger@de.ibm.com>

 *               Heiko Carstens <heiko.carstens@de.ibm.com>

 *               Christian Ehrhardt <ehrhardt@de.ibm.com>

 */



#include <linux/compiler.h>
@@ -278,16 +279,10 @@ static void kvm_s390_vcpu_initial_reset(struct kvm_vcpu *vcpu) 
	vcpu->arch.sie_block->gbea = 1;

}



/* The current code can have up to 256 pages for virtio */

#define VIRTIODESCSPACE (256ul * 4096ul)



int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)

{

	atomic_set(&vcpu->arch.sie_block->cpuflags, CPUSTAT_ZARCH);

	vcpu->arch.sie_block->gmslm = vcpu->kvm->arch.guest_memsize +

				      vcpu->kvm->arch.guest_origin +

				      VIRTIODESCSPACE - 1ul;

	vcpu->arch.sie_block->gmsor = vcpu->kvm->arch.guest_origin;

	set_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests);

	vcpu->arch.sie_block->ecb   = 2;

	vcpu->arch.sie_block->eca   = 0xC1002001U;

	vcpu->arch.sie_block->fac   = (int) (long) facilities;
@@ -491,9 +486,14 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	vcpu_load(vcpu);



rerun_vcpu:

	if (vcpu->requests)

		if (test_and_clear_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests))

			kvm_s390_vcpu_set_mem(vcpu);



	/* verify, that memory has been registered */

	if (!vcpu->kvm->arch.guest_memsize) {

	if (!vcpu->arch.sie_block->gmslm) {

		vcpu_put(vcpu);

		VCPU_EVENT(vcpu, 3, "%s", "no memory registered to run vcpu");

		return -EINVAL;

	}
@@ -691,7 +691,7 @@ int kvm_arch_set_memory_region(struct kvm *kvm, 
	   vmas. It is okay to mmap() and munmap() stuff in this slot after

	   doing this call at any time */



	if (mem->slot || kvm->arch.guest_memsize)

	if (mem->slot)

		return -EINVAL;



	if (mem->guest_phys_addr)
@@ -706,36 +706,18 @@ int kvm_arch_set_memory_region(struct kvm *kvm, 
	if (!user_alloc)

		return -EINVAL;



	/* lock all vcpus */

	for (i = 0; i < KVM_MAX_VCPUS; ++i) {

		if (!kvm->vcpus[i])

			continue;

		if (!mutex_trylock(&kvm->vcpus[i]->mutex))

			goto fail_out;

	}



	kvm->arch.guest_origin = mem->userspace_addr;

	kvm->arch.guest_memsize = mem->memory_size;



	/* update sie control blocks, and unlock all vcpus */

	/* request update of sie control block for all available vcpus */

	for (i = 0; i < KVM_MAX_VCPUS; ++i) {

		if (kvm->vcpus[i]) {

			kvm->vcpus[i]->arch.sie_block->gmsor =

				kvm->arch.guest_origin;

			kvm->vcpus[i]->arch.sie_block->gmslm =

				kvm->arch.guest_memsize +

				kvm->arch.guest_origin +

				VIRTIODESCSPACE - 1ul;

			mutex_unlock(&kvm->vcpus[i]->mutex);

			if (test_and_set_bit(KVM_REQ_MMU_RELOAD,

						&kvm->vcpus[i]->requests))

				continue;

			kvm_s390_inject_sigp_stop(kvm->vcpus[i],

						  ACTION_RELOADVCPU_ON_STOP);

		}

	}



	return 0;



fail_out:

	for (; i >= 0; i--)

		mutex_unlock(&kvm->vcpus[i]->mutex);

	return -EINVAL;

}



void kvm_arch_flush_shadow(struct kvm *kvm)

arch/s390/kvm/kvm-s390.h

+28 −1
Original line number Diff line number Diff line 
/*

 * kvm_s390.h -  definition for kvm on s390

 *

 * Copyright IBM Corp. 2008

 * Copyright IBM Corp. 2008,2009

 *

 * 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)
@@ -9,6 +9,7 @@ 
 *

 *    Author(s): Carsten Otte <cotte@de.ibm.com>

 *               Christian Borntraeger <borntraeger@de.ibm.com>

 *               Christian Ehrhardt <ehrhardt@de.ibm.com>

 */



#ifndef ARCH_S390_KVM_S390_H
@@ -18,6 +19,9 @@ 
#include <linux/kvm.h>

#include <linux/kvm_host.h>



/* The current code can have up to 256 pages for virtio */

#define VIRTIODESCSPACE (256ul * 4096ul)



typedef int (*intercept_handler_t)(struct kvm_vcpu *vcpu);



/* negativ values are error codes, positive values for internal conditions */
@@ -54,6 +58,29 @@ int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu, 
int kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code);

int kvm_s390_inject_sigp_stop(struct kvm_vcpu *vcpu, int action);



static inline int kvm_s390_vcpu_get_memsize(struct kvm_vcpu *vcpu)

{

	return vcpu->arch.sie_block->gmslm

		- vcpu->arch.sie_block->gmsor

		- VIRTIODESCSPACE + 1ul;

}



static inline void kvm_s390_vcpu_set_mem(struct kvm_vcpu *vcpu)

{

	struct kvm_memory_slot *mem;



	down_read(&vcpu->kvm->slots_lock);

	mem = &vcpu->kvm->memslots[0];



	vcpu->arch.sie_block->gmsor = mem->userspace_addr;

	vcpu->arch.sie_block->gmslm =

		mem->userspace_addr +

		(mem->npages << PAGE_SHIFT) +

		VIRTIODESCSPACE - 1ul;



	up_read(&vcpu->kvm->slots_lock);

}



/* implemented in priv.c */

int kvm_s390_handle_b2(struct kvm_vcpu *vcpu);