Commit 92c96321 authored by David Hildenbrand's avatar David Hildenbrand Committed by Christian Borntraeger
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KVM: s390: gaccess: introduce access modes 



We will need special handling when fetching instructions, so let's
introduce new guest access modes GACC_FETCH and GACC_STORE instead
of a write flag. An additional patch will then introduce GACC_IFETCH.

Reviewed-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 634790b8

arch/s390/kvm/gaccess.c

+23 −23
Original line number Diff line number Diff line
@@ -373,7 +373,7 @@ void ipte_unlock(struct kvm_vcpu *vcpu) 
}



static int ar_translation(struct kvm_vcpu *vcpu, union asce *asce, ar_t ar,

			  int write)

			  enum gacc_mode mode)

{

	union alet alet;

	struct ale ale;
@@ -454,7 +454,7 @@ static int ar_translation(struct kvm_vcpu *vcpu, union asce *asce, ar_t ar, 
		}

	}



	if (ale.fo == 1 && write)

	if (ale.fo == 1 && mode == GACC_STORE)

		return PGM_PROTECTION;



	asce->val = aste.asce;
@@ -477,7 +477,7 @@ enum { 
};



static int get_vcpu_asce(struct kvm_vcpu *vcpu, union asce *asce,

			 ar_t ar, int write)

			 ar_t ar, enum gacc_mode mode)

{

	int rc;

	psw_t *psw = &vcpu->arch.sie_block->gpsw;
@@ -486,7 +486,7 @@ static int get_vcpu_asce(struct kvm_vcpu *vcpu, union asce *asce, 


	memset(pgm, 0, sizeof(*pgm));

	tec_bits = (struct trans_exc_code_bits *)&pgm->trans_exc_code;

	tec_bits->fsi = write ? FSI_STORE : FSI_FETCH;

	tec_bits->fsi = mode == GACC_STORE ? FSI_STORE : FSI_FETCH;

	tec_bits->as = psw_bits(*psw).as;



	if (!psw_bits(*psw).t) {
@@ -506,7 +506,7 @@ static int get_vcpu_asce(struct kvm_vcpu *vcpu, union asce *asce, 
		asce->val = vcpu->arch.sie_block->gcr[13];

		return 0;

	case PSW_AS_ACCREG:

		rc = ar_translation(vcpu, asce, ar, write);

		rc = ar_translation(vcpu, asce, ar, mode);

		switch (rc) {

		case PGM_ALEN_TRANSLATION:

		case PGM_ALE_SEQUENCE:
@@ -538,7 +538,7 @@ static int deref_table(struct kvm *kvm, unsigned long gpa, unsigned long *val) 
 * @gva: guest virtual address

 * @gpa: points to where guest physical (absolute) address should be stored

 * @asce: effective asce

 * @write: indicates if access is a write access

 * @mode: indicates the access mode to be used

 *

 * Translate a guest virtual address into a guest absolute address by means

 * of dynamic address translation as specified by the architecture.
@@ -554,7 +554,7 @@ static int deref_table(struct kvm *kvm, unsigned long gpa, unsigned long *val) 
 */

static unsigned long guest_translate(struct kvm_vcpu *vcpu, unsigned long gva,

				     unsigned long *gpa, const union asce asce,

				     int write)

				     enum gacc_mode mode)

{

	union vaddress vaddr = {.addr = gva};

	union raddress raddr = {.addr = gva};
@@ -699,7 +699,7 @@ static unsigned long guest_translate(struct kvm_vcpu *vcpu, unsigned long gva, 
real_address:

	raddr.addr = kvm_s390_real_to_abs(vcpu, raddr.addr);

absolute_address:

	if (write && dat_protection)

	if (mode == GACC_STORE && dat_protection)

		return PGM_PROTECTION;

	if (kvm_is_error_gpa(vcpu->kvm, raddr.addr))

		return PGM_ADDRESSING;
@@ -728,7 +728,7 @@ static int low_address_protection_enabled(struct kvm_vcpu *vcpu, 


static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga,

			    unsigned long *pages, unsigned long nr_pages,

			    const union asce asce, int write)

			    const union asce asce, enum gacc_mode mode)

{

	struct kvm_s390_pgm_info *pgm = &vcpu->arch.pgm;

	psw_t *psw = &vcpu->arch.sie_block->gpsw;
@@ -740,13 +740,13 @@ static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga, 
	while (nr_pages) {

		ga = kvm_s390_logical_to_effective(vcpu, ga);

		tec_bits->addr = ga >> PAGE_SHIFT;

		if (write && lap_enabled && is_low_address(ga)) {

		if (mode == GACC_STORE && lap_enabled && is_low_address(ga)) {

			pgm->code = PGM_PROTECTION;

			return pgm->code;

		}

		ga &= PAGE_MASK;

		if (psw_bits(*psw).t) {

			rc = guest_translate(vcpu, ga, pages, asce, write);

			rc = guest_translate(vcpu, ga, pages, asce, mode);

			if (rc < 0)

				return rc;

			if (rc == PGM_PROTECTION)
@@ -768,7 +768,7 @@ static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga, 
}



int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,

		 unsigned long len, int write)

		 unsigned long len, enum gacc_mode mode)

{

	psw_t *psw = &vcpu->arch.sie_block->gpsw;

	unsigned long _len, nr_pages, gpa, idx;
@@ -780,7 +780,7 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data, 


	if (!len)

		return 0;

	rc = get_vcpu_asce(vcpu, &asce, ar, write);

	rc = get_vcpu_asce(vcpu, &asce, ar, mode);

	if (rc)

		return rc;

	nr_pages = (((ga & ~PAGE_MASK) + len - 1) >> PAGE_SHIFT) + 1;
@@ -792,11 +792,11 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data, 
	need_ipte_lock = psw_bits(*psw).t && !asce.r;

	if (need_ipte_lock)

		ipte_lock(vcpu);

	rc = guest_page_range(vcpu, ga, pages, nr_pages, asce, write);

	rc = guest_page_range(vcpu, ga, pages, nr_pages, asce, mode);

	for (idx = 0; idx < nr_pages && !rc; idx++) {

		gpa = *(pages + idx) + (ga & ~PAGE_MASK);

		_len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len);

		if (write)

		if (mode == GACC_STORE)

			rc = kvm_write_guest(vcpu->kvm, gpa, data, _len);

		else

			rc = kvm_read_guest(vcpu->kvm, gpa, data, _len);
@@ -812,7 +812,7 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data, 
}



int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,

		      void *data, unsigned long len, int write)

		      void *data, unsigned long len, enum gacc_mode mode)

{

	unsigned long _len, gpa;

	int rc = 0;
@@ -820,7 +820,7 @@ int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, 
	while (len && !rc) {

		gpa = kvm_s390_real_to_abs(vcpu, gra);

		_len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len);

		if (write)

		if (mode)

			rc = write_guest_abs(vcpu, gpa, data, _len);

		else

			rc = read_guest_abs(vcpu, gpa, data, _len);
@@ -841,7 +841,7 @@ int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, 
 * has to take care of this.

 */

int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar,

			    unsigned long *gpa, int write)

			    unsigned long *gpa, enum gacc_mode mode)

{

	struct kvm_s390_pgm_info *pgm = &vcpu->arch.pgm;

	psw_t *psw = &vcpu->arch.sie_block->gpsw;
@@ -851,19 +851,19 @@ int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar, 


	gva = kvm_s390_logical_to_effective(vcpu, gva);

	tec = (struct trans_exc_code_bits *)&pgm->trans_exc_code;

	rc = get_vcpu_asce(vcpu, &asce, ar, write);

	rc = get_vcpu_asce(vcpu, &asce, ar, mode);

	tec->addr = gva >> PAGE_SHIFT;

	if (rc)

		return rc;

	if (is_low_address(gva) && low_address_protection_enabled(vcpu, asce)) {

		if (write) {

		if (mode == GACC_STORE) {

			rc = pgm->code = PGM_PROTECTION;

			return rc;

		}

	}



	if (psw_bits(*psw).t && !asce.r) {	/* Use DAT? */

		rc = guest_translate(vcpu, gva, gpa, asce, write);

		rc = guest_translate(vcpu, gva, gpa, asce, mode);

		if (rc > 0) {

			if (rc == PGM_PROTECTION)

				tec->b61 = 1;
@@ -883,7 +883,7 @@ int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar, 
 * check_gva_range - test a range of guest virtual addresses for accessibility

 */

int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar,

		    unsigned long length, int is_write)

		    unsigned long length, enum gacc_mode mode)

{

	unsigned long gpa;

	unsigned long currlen;
@@ -892,7 +892,7 @@ int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar, 
	ipte_lock(vcpu);

	while (length > 0 && !rc) {

		currlen = min(length, PAGE_SIZE - (gva % PAGE_SIZE));

		rc = guest_translate_address(vcpu, gva, ar, &gpa, is_write);

		rc = guest_translate_address(vcpu, gva, ar, &gpa, mode);

		gva += currlen;

		length -= currlen;

	}

arch/s390/kvm/gaccess.h

+11 −6
Original line number Diff line number Diff line
@@ -155,16 +155,21 @@ int read_guest_lc(struct kvm_vcpu *vcpu, unsigned long gra, void *data, 
	return kvm_read_guest(vcpu->kvm, gpa, data, len);

}



enum gacc_mode {

	GACC_FETCH,

	GACC_STORE,

};



int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva,

			    ar_t ar, unsigned long *gpa, int write);

			    ar_t ar, unsigned long *gpa, enum gacc_mode mode);

int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar,

		    unsigned long length, int is_write);

		    unsigned long length, enum gacc_mode mode);



int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,

		 unsigned long len, int write);

		 unsigned long len, enum gacc_mode mode);



int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,

		      void *data, unsigned long len, int write);

		      void *data, unsigned long len, enum gacc_mode mode);



/**

 * write_guest - copy data from kernel space to guest space
@@ -215,7 +220,7 @@ static inline __must_check 
int write_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,

		unsigned long len)

{

	return access_guest(vcpu, ga, ar, data, len, 1);

	return access_guest(vcpu, ga, ar, data, len, GACC_STORE);

}



/**
@@ -235,7 +240,7 @@ static inline __must_check 
int read_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,

	       unsigned long len)

{

	return access_guest(vcpu, ga, ar, data, len, 0);

	return access_guest(vcpu, ga, ar, data, len, GACC_FETCH);

}



/**

arch/s390/kvm/intercept.c

+2 −2
Original line number Diff line number Diff line
@@ -317,7 +317,7 @@ static int handle_mvpg_pei(struct kvm_vcpu *vcpu) 


	/* Make sure that the source is paged-in */

	rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg2],

				     reg2, &srcaddr, 0);

				     reg2, &srcaddr, GACC_FETCH);

	if (rc)

		return kvm_s390_inject_prog_cond(vcpu, rc);

	rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
@@ -326,7 +326,7 @@ static int handle_mvpg_pei(struct kvm_vcpu *vcpu) 


	/* Make sure that the destination is paged-in */

	rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg1],

				     reg1, &dstaddr, 1);

				     reg1, &dstaddr, GACC_STORE);

	if (rc)

		return kvm_s390_inject_prog_cond(vcpu, rc);

	rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);

arch/s390/kvm/kvm-s390.c

+4 −2
Original line number Diff line number Diff line
@@ -2610,7 +2610,8 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu, 
	switch (mop->op) {

	case KVM_S390_MEMOP_LOGICAL_READ:

		if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {

			r = check_gva_range(vcpu, mop->gaddr, mop->ar, mop->size, false);

			r = check_gva_range(vcpu, mop->gaddr, mop->ar,

					    mop->size, GACC_FETCH);

			break;

		}

		r = read_guest(vcpu, mop->gaddr, mop->ar, tmpbuf, mop->size);
@@ -2621,7 +2622,8 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu, 
		break;

	case KVM_S390_MEMOP_LOGICAL_WRITE:

		if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {

			r = check_gva_range(vcpu, mop->gaddr, mop->ar, mop->size, true);

			r = check_gva_range(vcpu, mop->gaddr, mop->ar,

					    mop->size, GACC_STORE);

			break;

		}

		if (copy_from_user(tmpbuf, uaddr, mop->size)) {

arch/s390/kvm/priv.c

+3 −2
Original line number Diff line number Diff line
@@ -981,11 +981,12 @@ static int handle_tprot(struct kvm_vcpu *vcpu) 
		return -EOPNOTSUPP;

	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)

		ipte_lock(vcpu);

	ret = guest_translate_address(vcpu, address1, ar, &gpa, 1);

	ret = guest_translate_address(vcpu, address1, ar, &gpa, GACC_STORE);

	if (ret == PGM_PROTECTION) {

		/* Write protected? Try again with read-only... */

		cc = 1;

		ret = guest_translate_address(vcpu, address1, ar, &gpa, 0);

		ret = guest_translate_address(vcpu, address1, ar, &gpa,

					      GACC_FETCH);

	}

	if (ret) {

		if (ret == PGM_ADDRESSING || ret == PGM_TRANSLATION_SPEC) {

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