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| author | David Hildenbrand <dahi@linux.vnet.ibm.com> | 2015-07-08 13:25:31 +0200 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2016-06-21 09:43:44 +0200 |
| commit | 1b7029bec18718eca8cfc5c1c0917444f019be1e (patch) | |
| tree | 3be941cf36af3b2c6b40a2b6ff691626c5fffd79 /arch/s390 | |
| parent | 7fd7f39daa3da822122124730437c4f37e4d82de (diff) | |
| download | linux-0-day-1b7029bec18718eca8cfc5c1c0917444f019be1e.tar.gz linux-0-day-1b7029bec18718eca8cfc5c1c0917444f019be1e.tar.xz | |
KVM: s390: vsie: try to refault after a reported fault to g2
We can avoid one unneeded SIE entry after we reported a fault to g2.
Theoretically, g2 resolves the fault and we can create the shadow mapping
directly, instead of failing again when entering the SIE.
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/kvm/vsie.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index 3ececbbd6bb08..7482488d21d0a 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -28,7 +28,9 @@ struct vsie_page { struct kvm_s390_sie_block *scb_o; /* 0x0200 */ /* the shadow gmap in use by the vsie_page */ struct gmap *gmap; /* 0x0208 */ - __u8 reserved[0x0700 - 0x0210]; /* 0x0210 */ + /* address of the last reported fault to guest2 */ + unsigned long fault_addr; /* 0x0210 */ + __u8 reserved[0x0700 - 0x0218]; /* 0x0218 */ struct kvm_s390_crypto_cb crycb; /* 0x0700 */ __u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE]; /* 0x0800 */ } __packed; @@ -676,10 +678,27 @@ static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) rc = inject_fault(vcpu, rc, current->thread.gmap_addr, current->thread.gmap_write_flag); + if (rc >= 0) + vsie_page->fault_addr = current->thread.gmap_addr; } return rc; } +/* + * Retry the previous fault that required guest 2 intervention. This avoids + * one superfluous SIE re-entry and direct exit. + * + * Will ignore any errors. The next SIE fault will do proper fault handling. + */ +static void handle_last_fault(struct kvm_vcpu *vcpu, + struct vsie_page *vsie_page) +{ + if (vsie_page->fault_addr) + kvm_s390_shadow_fault(vcpu, vsie_page->gmap, + vsie_page->fault_addr); + vsie_page->fault_addr = 0; +} + static inline void clear_vsie_icpt(struct vsie_page *vsie_page) { vsie_page->scb_s.icptcode = 0; @@ -737,6 +756,8 @@ static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; int rc; + handle_last_fault(vcpu, vsie_page); + if (need_resched()) schedule(); if (test_cpu_flag(CIF_MCCK_PENDING)) @@ -928,6 +949,7 @@ static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr) vsie_page = page_to_virt(page); memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block)); release_gmap_shadow(vsie_page); + vsie_page->fault_addr = 0; vsie_page->scb_s.ihcpu = 0xffffU; return vsie_page; } |