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KVM: s390: Optimize paths where get_vcpu_asce() is invoked

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During dynamic address translation the get_vcpu_asce()
function can be invoked several times. It's ok for usual modes, but will
be slow if CPUs are in AR mode. Let's call the get_vcpu_asce() once and
pass the result to the called functions.

Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
Alexander Yarygin 2015-01-22 12:44:11 +03:00 committed by Christian Borntraeger
parent 8ae04b8f50
commit 75a1812230
1 changed files with 12 additions and 13 deletions
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25
arch/s390/kvm/gaccess.c
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@ -330,6 +330,7 @@ static int deref_table(struct kvm *kvm, unsigned long gpa, unsigned long *val)
* @vcpu: virtual cpu
* @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
*
* Translate a guest virtual address into a guest absolute address by means
@ -345,7 +346,8 @@ static int deref_table(struct kvm *kvm, unsigned long gpa, unsigned long *val)
* by the architecture
*/
static unsigned long guest_translate(struct kvm_vcpu *vcpu, unsigned long gva,
unsigned long *gpa, int write)
unsigned long *gpa, const union asce asce,
int write)
{
union vaddress vaddr = {.addr = gva};
union raddress raddr = {.addr = gva};
@ -354,12 +356,10 @@ static unsigned long guest_translate(struct kvm_vcpu *vcpu, unsigned long gva,
union ctlreg0 ctlreg0;
unsigned long ptr;
int edat1, edat2;
union asce asce;
ctlreg0.val = vcpu->arch.sie_block->gcr[0];
edat1 = ctlreg0.edat && test_kvm_facility(vcpu->kvm, 8);
edat2 = edat1 && test_kvm_facility(vcpu->kvm, 78);
asce.val = get_vcpu_asce(vcpu);
if (asce.r)
goto real_address;
ptr = asce.origin * 4096;
@ -506,15 +506,14 @@ static inline int is_low_address(unsigned long ga)
return (ga & ~0x11fful) == 0;
}
static int low_address_protection_enabled(struct kvm_vcpu *vcpu)
static int low_address_protection_enabled(struct kvm_vcpu *vcpu,
const union asce asce)
{
union ctlreg0 ctlreg0 = {.val = vcpu->arch.sie_block->gcr[0]};
psw_t *psw = &vcpu->arch.sie_block->gpsw;
union asce asce;
if (!ctlreg0.lap)
return 0;
asce.val = get_vcpu_asce(vcpu);
if (psw_bits(*psw).t && asce.p)
return 0;
return 1;
@ -536,7 +535,7 @@ enum {
static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga,
unsigned long *pages, unsigned long nr_pages,
int write)
const union asce asce, int write)
{
struct kvm_s390_pgm_info *pgm = &vcpu->arch.pgm;
psw_t *psw = &vcpu->arch.sie_block->gpsw;
@ -547,7 +546,7 @@ static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga,
tec_bits = (struct trans_exc_code_bits *)&pgm->trans_exc_code;
tec_bits->fsi = write ? FSI_STORE : FSI_FETCH;
tec_bits->as = psw_bits(*psw).as;
lap_enabled = low_address_protection_enabled(vcpu);
lap_enabled = low_address_protection_enabled(vcpu, asce);
while (nr_pages) {
ga = kvm_s390_logical_to_effective(vcpu, ga);
tec_bits->addr = ga >> PAGE_SHIFT;
@ -557,7 +556,7 @@ static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga,
}
ga &= PAGE_MASK;
if (psw_bits(*psw).t) {
rc = guest_translate(vcpu, ga, pages, write);
rc = guest_translate(vcpu, ga, pages, asce, write);
if (rc < 0)
return rc;
if (rc == PGM_PROTECTION)
@ -604,7 +603,7 @@ 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, write);
rc = guest_page_range(vcpu, ga, pages, nr_pages, asce, write);
for (idx = 0; idx < nr_pages && !rc; idx++) {
gpa = *(pages + idx) + (ga & ~PAGE_MASK);
_len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len);
@ -671,16 +670,16 @@ int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar,
tec->as = psw_bits(*psw).as;
tec->fsi = write ? FSI_STORE : FSI_FETCH;
tec->addr = gva >> PAGE_SHIFT;
if (is_low_address(gva) && low_address_protection_enabled(vcpu)) {
asce.val = get_vcpu_asce(vcpu);
if (is_low_address(gva) && low_address_protection_enabled(vcpu, asce)) {
if (write) {
rc = pgm->code = PGM_PROTECTION;
return rc;
}
}
asce.val = get_vcpu_asce(vcpu);
if (psw_bits(*psw).t && !asce.r) { /* Use DAT? */
rc = guest_translate(vcpu, gva, gpa, write);
rc = guest_translate(vcpu, gva, gpa, asce, write);
if (rc > 0) {
if (rc == PGM_PROTECTION)
tec->b61 = 1;