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authorPaolo Bonzini <pbonzini@redhat.com>2021-04-15 13:02:13 -0400
committerPaolo Bonzini <pbonzini@redhat.com>2021-04-15 13:02:13 -0400
commit6c377b02a801801b04ec6e5f9a921fca83ff9e54 (patch)
tree6e3c76a01eec534970aef2ae6a07165b30be6576 /arch/s390
parent657f1d86a38e4b5d13551948c02cc8fc6987e3a5 (diff)
parentc3171e94cc1cdcc3229565244112e869f052b8d9 (diff)
Merge tag 'kvm-s390-next-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
KVM: s390: Updates for 5.13 - properly handle MVPG in nesting KVM (vsie) - allow to forward the yield_to hypercall (diagnose 9c) - fixes
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/include/asm/kvm_host.h1
-rw-r--r--arch/s390/include/asm/smp.h1
-rw-r--r--arch/s390/kernel/smp.c1
-rw-r--r--arch/s390/kvm/diag.c31
-rw-r--r--arch/s390/kvm/gaccess.c30
-rw-r--r--arch/s390/kvm/gaccess.h60
-rw-r--r--arch/s390/kvm/kvm-s390.c8
-rw-r--r--arch/s390/kvm/kvm-s390.h8
-rw-r--r--arch/s390/kvm/vsie.c109
9 files changed, 217 insertions, 32 deletions
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 6bcfc5614bbc..0af3e032a49d 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -454,6 +454,7 @@ struct kvm_vcpu_stat {
u64 diagnose_44;
u64 diagnose_9c;
u64 diagnose_9c_ignored;
+ u64 diagnose_9c_forward;
u64 diagnose_258;
u64 diagnose_308;
u64 diagnose_500;
diff --git a/arch/s390/include/asm/smp.h b/arch/s390/include/asm/smp.h
index 01e360004481..e317fd4866c1 100644
--- a/arch/s390/include/asm/smp.h
+++ b/arch/s390/include/asm/smp.h
@@ -63,5 +63,6 @@ extern void __noreturn cpu_die(void);
extern void __cpu_die(unsigned int cpu);
extern int __cpu_disable(void);
extern void schedule_mcck_handler(void);
+void notrace smp_yield_cpu(int cpu);
#endif /* __ASM_SMP_H */
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 58c8afa3da65..2fec2b80d35d 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -429,6 +429,7 @@ void notrace smp_yield_cpu(int cpu)
asm volatile("diag %0,0,0x9c"
: : "d" (pcpu_devices[cpu].address));
}
+EXPORT_SYMBOL_GPL(smp_yield_cpu);
/*
* Send cpus emergency shutdown signal. This gives the cpus the
diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
index 5b8ec1c447e1..02c146f9e5cd 100644
--- a/arch/s390/kvm/diag.c
+++ b/arch/s390/kvm/diag.c
@@ -150,6 +150,19 @@ static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
return 0;
}
+static int forward_cnt;
+static unsigned long cur_slice;
+
+static int diag9c_forwarding_overrun(void)
+{
+ /* Reset the count on a new slice */
+ if (time_after(jiffies, cur_slice)) {
+ cur_slice = jiffies;
+ forward_cnt = diag9c_forwarding_hz / HZ;
+ }
+ return forward_cnt-- <= 0 ? 1 : 0;
+}
+
static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu *tcpu;
@@ -167,9 +180,21 @@ static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
if (!tcpu)
goto no_yield;
- /* target already running */
- if (READ_ONCE(tcpu->cpu) >= 0)
- goto no_yield;
+ /* target guest VCPU already running */
+ if (READ_ONCE(tcpu->cpu) >= 0) {
+ if (!diag9c_forwarding_hz || diag9c_forwarding_overrun())
+ goto no_yield;
+
+ /* target host CPU already running */
+ if (!vcpu_is_preempted(tcpu->cpu))
+ goto no_yield;
+ smp_yield_cpu(tcpu->cpu);
+ VCPU_EVENT(vcpu, 5,
+ "diag time slice end directed to %d: yield forwarded",
+ tid);
+ vcpu->stat.diagnose_9c_forward++;
+ return 0;
+ }
if (kvm_vcpu_yield_to(tcpu) <= 0)
goto no_yield;
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 6d6b57059493..b9f85b2dc053 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -976,7 +976,9 @@ int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu *vcpu, unsigned long gra)
* kvm_s390_shadow_tables - walk the guest page table and create shadow tables
* @sg: pointer to the shadow guest address space structure
* @saddr: faulting address in the shadow gmap
- * @pgt: pointer to the page table address result
+ * @pgt: pointer to the beginning of the page table for the given address if
+ * successful (return value 0), or to the first invalid DAT entry in
+ * case of exceptions (return value > 0)
* @fake: pgt references contiguous guest memory block, not a pgtable
*/
static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
@@ -1034,6 +1036,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
rfte.val = ptr;
goto shadow_r2t;
}
+ *pgt = ptr + vaddr.rfx * 8;
rc = gmap_read_table(parent, ptr + vaddr.rfx * 8, &rfte.val);
if (rc)
return rc;
@@ -1060,6 +1063,7 @@ shadow_r2t:
rste.val = ptr;
goto shadow_r3t;
}
+ *pgt = ptr + vaddr.rsx * 8;
rc = gmap_read_table(parent, ptr + vaddr.rsx * 8, &rste.val);
if (rc)
return rc;
@@ -1087,6 +1091,7 @@ shadow_r3t:
rtte.val = ptr;
goto shadow_sgt;
}
+ *pgt = ptr + vaddr.rtx * 8;
rc = gmap_read_table(parent, ptr + vaddr.rtx * 8, &rtte.val);
if (rc)
return rc;
@@ -1123,6 +1128,7 @@ shadow_sgt:
ste.val = ptr;
goto shadow_pgt;
}
+ *pgt = ptr + vaddr.sx * 8;
rc = gmap_read_table(parent, ptr + vaddr.sx * 8, &ste.val);
if (rc)
return rc;
@@ -1157,6 +1163,8 @@ shadow_pgt:
* @vcpu: virtual cpu
* @sg: pointer to the shadow guest address space structure
* @saddr: faulting address in the shadow gmap
+ * @datptr: will contain the address of the faulting DAT table entry, or of
+ * the valid leaf, plus some flags
*
* Returns: - 0 if the shadow fault was successfully resolved
* - > 0 (pgm exception code) on exceptions while faulting
@@ -1165,11 +1173,11 @@ shadow_pgt:
* - -ENOMEM if out of memory
*/
int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *sg,
- unsigned long saddr)
+ unsigned long saddr, unsigned long *datptr)
{
union vaddress vaddr;
union page_table_entry pte;
- unsigned long pgt;
+ unsigned long pgt = 0;
int dat_protection, fake;
int rc;
@@ -1191,8 +1199,20 @@ int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *sg,
pte.val = pgt + vaddr.px * PAGE_SIZE;
goto shadow_page;
}
- if (!rc)
- rc = gmap_read_table(sg->parent, pgt + vaddr.px * 8, &pte.val);
+
+ switch (rc) {
+ case PGM_SEGMENT_TRANSLATION:
+ case PGM_REGION_THIRD_TRANS:
+ case PGM_REGION_SECOND_TRANS:
+ case PGM_REGION_FIRST_TRANS:
+ pgt |= PEI_NOT_PTE;
+ break;
+ case 0:
+ pgt += vaddr.px * 8;
+ rc = gmap_read_table(sg->parent, pgt, &pte.val);
+ }
+ if (datptr)
+ *datptr = pgt | dat_protection * PEI_DAT_PROT;
if (!rc && pte.i)
rc = PGM_PAGE_TRANSLATION;
if (!rc && pte.z)
diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/gaccess.h
index f4c51756c462..7c72a5e3449f 100644
--- a/arch/s390/kvm/gaccess.h
+++ b/arch/s390/kvm/gaccess.h
@@ -18,17 +18,14 @@
/**
* kvm_s390_real_to_abs - convert guest real address to guest absolute address
- * @vcpu - guest virtual cpu
+ * @prefix - guest prefix
* @gra - guest real address
*
* Returns the guest absolute address that corresponds to the passed guest real
- * address @gra of a virtual guest cpu by applying its prefix.
+ * address @gra of by applying the given prefix.
*/
-static inline unsigned long kvm_s390_real_to_abs(struct kvm_vcpu *vcpu,
- unsigned long gra)
+static inline unsigned long _kvm_s390_real_to_abs(u32 prefix, unsigned long gra)
{
- unsigned long prefix = kvm_s390_get_prefix(vcpu);
-
if (gra < 2 * PAGE_SIZE)
gra += prefix;
else if (gra >= prefix && gra < prefix + 2 * PAGE_SIZE)
@@ -37,6 +34,43 @@ static inline unsigned long kvm_s390_real_to_abs(struct kvm_vcpu *vcpu,
}
/**
+ * kvm_s390_real_to_abs - convert guest real address to guest absolute address
+ * @vcpu - guest virtual cpu
+ * @gra - guest real address
+ *
+ * Returns the guest absolute address that corresponds to the passed guest real
+ * address @gra of a virtual guest cpu by applying its prefix.
+ */
+static inline unsigned long kvm_s390_real_to_abs(struct kvm_vcpu *vcpu,
+ unsigned long gra)
+{
+ return _kvm_s390_real_to_abs(kvm_s390_get_prefix(vcpu), gra);
+}
+
+/**
+ * _kvm_s390_logical_to_effective - convert guest logical to effective address
+ * @psw: psw of the guest
+ * @ga: guest logical address
+ *
+ * Convert a guest logical address to an effective address by applying the
+ * rules of the addressing mode defined by bits 31 and 32 of the given PSW
+ * (extendended/basic addressing mode).
+ *
+ * Depending on the addressing mode, the upper 40 bits (24 bit addressing
+ * mode), 33 bits (31 bit addressing mode) or no bits (64 bit addressing
+ * mode) of @ga will be zeroed and the remaining bits will be returned.
+ */
+static inline unsigned long _kvm_s390_logical_to_effective(psw_t *psw,
+ unsigned long ga)
+{
+ if (psw_bits(*psw).eaba == PSW_BITS_AMODE_64BIT)
+ return ga;
+ if (psw_bits(*psw).eaba == PSW_BITS_AMODE_31BIT)
+ return ga & ((1UL << 31) - 1);
+ return ga & ((1UL << 24) - 1);
+}
+
+/**
* kvm_s390_logical_to_effective - convert guest logical to effective address
* @vcpu: guest virtual cpu
* @ga: guest logical address
@@ -52,13 +86,7 @@ static inline unsigned long kvm_s390_real_to_abs(struct kvm_vcpu *vcpu,
static inline unsigned long kvm_s390_logical_to_effective(struct kvm_vcpu *vcpu,
unsigned long ga)
{
- psw_t *psw = &vcpu->arch.sie_block->gpsw;
-
- if (psw_bits(*psw).eaba == PSW_BITS_AMODE_64BIT)
- return ga;
- if (psw_bits(*psw).eaba == PSW_BITS_AMODE_31BIT)
- return ga & ((1UL << 31) - 1);
- return ga & ((1UL << 24) - 1);
+ return _kvm_s390_logical_to_effective(&vcpu->arch.sie_block->gpsw, ga);
}
/*
@@ -359,7 +387,11 @@ void ipte_unlock(struct kvm_vcpu *vcpu);
int ipte_lock_held(struct kvm_vcpu *vcpu);
int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu *vcpu, unsigned long gra);
+/* MVPG PEI indication bits */
+#define PEI_DAT_PROT 2
+#define PEI_NOT_PTE 4
+
int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *shadow,
- unsigned long saddr);
+ unsigned long saddr, unsigned long *datptr);
#endif /* __KVM_S390_GACCESS_H */
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 2f09e9d7dc95..cfe720d16a6a 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -158,6 +158,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
VCPU_STAT("instruction_diag_44", diagnose_44),
VCPU_STAT("instruction_diag_9c", diagnose_9c),
VCPU_STAT("diag_9c_ignored", diagnose_9c_ignored),
+ VCPU_STAT("diag_9c_forward", diagnose_9c_forward),
VCPU_STAT("instruction_diag_258", diagnose_258),
VCPU_STAT("instruction_diag_308", diagnose_308),
VCPU_STAT("instruction_diag_500", diagnose_500),
@@ -185,6 +186,11 @@ static bool use_gisa = true;
module_param(use_gisa, bool, 0644);
MODULE_PARM_DESC(use_gisa, "Use the GISA if the host supports it.");
+/* maximum diag9c forwarding per second */
+unsigned int diag9c_forwarding_hz;
+module_param(diag9c_forwarding_hz, uint, 0644);
+MODULE_PARM_DESC(diag9c_forwarding_hz, "Maximum diag9c forwarding per second, 0 to turn off");
+
/*
* For now we handle at most 16 double words as this is what the s390 base
* kernel handles and stores in the prefix page. If we ever need to go beyond
@@ -4542,7 +4548,7 @@ int kvm_s390_vcpu_start(struct kvm_vcpu *vcpu)
/*
* As we are starting a second VCPU, we have to disable
* the IBS facility on all VCPUs to remove potentially
- * oustanding ENABLE requests.
+ * outstanding ENABLE requests.
*/
__disable_ibs_on_all_vcpus(vcpu->kvm);
}
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index 79dcd647b378..9fad25109b0d 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -471,4 +471,12 @@ void kvm_s390_reinject_machine_check(struct kvm_vcpu *vcpu,
* @kvm: the KVM guest
*/
void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm);
+
+/**
+ * diag9c_forwarding_hz
+ *
+ * Set the maximum number of diag9c forwarding per second
+ */
+extern unsigned int diag9c_forwarding_hz;
+
#endif
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index bd803e091918..4002a24bc43a 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -417,11 +417,6 @@ static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
memcpy((void *)((u64)scb_o + 0xc0),
(void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0);
break;
- case ICPT_PARTEXEC:
- /* MVPG only */
- memcpy((void *)((u64)scb_o + 0xc0),
- (void *)((u64)scb_s + 0xc0), 0xd0 - 0xc0);
- break;
}
if (scb_s->ihcpu != 0xffffU)
@@ -620,10 +615,10 @@ static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
/* with mso/msl, the prefix lies at offset *mso* */
prefix += scb_s->mso;
- rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix);
+ rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix, NULL);
if (!rc && (scb_s->ecb & ECB_TE))
rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
- prefix + PAGE_SIZE);
+ prefix + PAGE_SIZE, NULL);
/*
* We don't have to mprotect, we will be called for all unshadows.
* SIE will detect if protection applies and trigger a validity.
@@ -914,7 +909,7 @@ static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
current->thread.gmap_addr, 1);
rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
- current->thread.gmap_addr);
+ current->thread.gmap_addr, NULL);
if (rc > 0) {
rc = inject_fault(vcpu, rc,
current->thread.gmap_addr,
@@ -936,7 +931,7 @@ static void handle_last_fault(struct kvm_vcpu *vcpu,
{
if (vsie_page->fault_addr)
kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
- vsie_page->fault_addr);
+ vsie_page->fault_addr, NULL);
vsie_page->fault_addr = 0;
}
@@ -984,6 +979,98 @@ static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
}
/*
+ * Get a register for a nested guest.
+ * @vcpu the vcpu of the guest
+ * @vsie_page the vsie_page for the nested guest
+ * @reg the register number, the upper 4 bits are ignored.
+ * returns: the value of the register.
+ */
+static u64 vsie_get_register(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, u8 reg)
+{
+ /* no need to validate the parameter and/or perform error handling */
+ reg &= 0xf;
+ switch (reg) {
+ case 15:
+ return vsie_page->scb_s.gg15;
+ case 14:
+ return vsie_page->scb_s.gg14;
+ default:
+ return vcpu->run->s.regs.gprs[reg];
+ }
+}
+
+static int vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
+{
+ struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
+ unsigned long pei_dest, pei_src, src, dest, mask, prefix;
+ u64 *pei_block = &vsie_page->scb_o->mcic;
+ int edat, rc_dest, rc_src;
+ union ctlreg0 cr0;
+
+ cr0.val = vcpu->arch.sie_block->gcr[0];
+ edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8);
+ mask = _kvm_s390_logical_to_effective(&scb_s->gpsw, PAGE_MASK);
+ prefix = scb_s->prefix << GUEST_PREFIX_SHIFT;
+
+ dest = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 20) & mask;
+ dest = _kvm_s390_real_to_abs(prefix, dest) + scb_s->mso;
+ src = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 16) & mask;
+ src = _kvm_s390_real_to_abs(prefix, src) + scb_s->mso;
+
+ rc_dest = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, dest, &pei_dest);
+ rc_src = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, src, &pei_src);
+ /*
+ * Either everything went well, or something non-critical went wrong
+ * e.g. because of a race. In either case, simply retry.
+ */
+ if (rc_dest == -EAGAIN || rc_src == -EAGAIN || (!rc_dest && !rc_src)) {
+ retry_vsie_icpt(vsie_page);
+ return -EAGAIN;
+ }
+ /* Something more serious went wrong, propagate the error */
+ if (rc_dest < 0)
+ return rc_dest;
+ if (rc_src < 0)
+ return rc_src;
+
+ /* The only possible suppressing exception: just deliver it */
+ if (rc_dest == PGM_TRANSLATION_SPEC || rc_src == PGM_TRANSLATION_SPEC) {
+ clear_vsie_icpt(vsie_page);
+ rc_dest = kvm_s390_inject_program_int(vcpu, PGM_TRANSLATION_SPEC);
+ WARN_ON_ONCE(rc_dest);
+ return 1;
+ }
+
+ /*
+ * Forward the PEI intercept to the guest if it was a page fault, or
+ * also for segment and region table faults if EDAT applies.
+ */
+ if (edat) {
+ rc_dest = rc_dest == PGM_ASCE_TYPE ? rc_dest : 0;
+ rc_src = rc_src == PGM_ASCE_TYPE ? rc_src : 0;
+ } else {
+ rc_dest = rc_dest != PGM_PAGE_TRANSLATION ? rc_dest : 0;
+ rc_src = rc_src != PGM_PAGE_TRANSLATION ? rc_src : 0;
+ }
+ if (!rc_dest && !rc_src) {
+ pei_block[0] = pei_dest;
+ pei_block[1] = pei_src;
+ return 1;
+ }
+
+ retry_vsie_icpt(vsie_page);
+
+ /*
+ * The host has edat, and the guest does not, or it was an ASCE type
+ * exception. The host needs to inject the appropriate DAT interrupts
+ * into the guest.
+ */
+ if (rc_dest)
+ return inject_fault(vcpu, rc_dest, dest, 1);
+ return inject_fault(vcpu, rc_src, src, 0);
+}
+
+/*
* Run the vsie on a shadow scb and a shadow gmap, without any further
* sanity checks, handling SIE faults.
*
@@ -1071,6 +1158,10 @@ static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
if ((scb_s->ipa & 0xf000) != 0xf000)
scb_s->ipa += 0x1000;
break;
+ case ICPT_PARTEXEC:
+ if (scb_s->ipa == 0xb254)
+ rc = vsie_handle_mvpg(vcpu, vsie_page);
+ break;
}
return rc;
}