| Message ID | 20210223191353.267981-3-imbrenda@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390/kvm: fix MVPG when in VSIE | expand |
On 23.02.21 20:13, Claudio Imbrenda wrote: > Correctly handle the MVPG instruction when issued by a VSIE guest. > > Fixes: a3508fbe9dc6d ("KVM: s390: vsie: initial support for nested virtualization") > Cc: stable@vger.kernel.org > Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> > Acked-by: Janosch Frank <frankja@linux.ibm.com> > --- > arch/s390/kvm/vsie.c | 93 +++++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 88 insertions(+), 5 deletions(-) > > diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c > index 78b604326016..dbf4241bc2dc 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) > @@ -983,6 +978,90 @@ static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) > return 0; > } > > +static u64 vsie_get_register(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, u8 reg) > +{ > + reg &= 0xf; Nit, I'd mask of that value in the caller where you extract it from the ipb. ... > +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 = PAGE_MASK; > + u64 *pei_block = &vsie_page->scb_o->mcic; > + int edat, rc_dest, rc_src; > + union ctlreg0 cr0; ... const uint8_t r1 = (scb_s->ipb >> 16) & 0xf; const uint8_t r3 = (scb_s->ipb >> 20) & 0xf; (note: r1/r3 is just a guess ;) - and having the actual identifiers here will make the code easier to understand) > + > + cr0.val = vcpu->arch.sie_block->gcr[0]; > + edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8); > + if (psw_bits(scb_s->gpsw).eaba == PSW_BITS_AMODE_24BIT) What about factoring out that masking like kvm_s390_logical_to_effective() introduce vsie_logical_to_effective() to handle that. > + mask = 0xfff000; > + else if (psw_bits(scb_s->gpsw).eaba == PSW_BITS_AMODE_31BIT) > + mask = 0x7ffff000; > + > + dest = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 16) & mask; > + src = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 20) & mask; > + > + 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. beause of a race. In either case, simply retry. s/beause/because/ > + */ > + if (rc_dest == -EAGAIN || rc_src == -EAGAIN || (!rc_dest && !rc_src)) { > + retry_vsie_icpt(vsie_page); > + return -EAGAIN; I remember, because of the retry_vsie_icpt() you can simply return 0. Whatever you prefer. > + } > + /* 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); The rc_dest and rc_src handling towards the end is a little confusing, but I have no real suggestion to make it easier to digest. Only some suggestions to make the code a bit nicer to read. Apart from that LGTM. Reviewed-by: David Hildenbrand <david@redhat.com>
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index 78b604326016..dbf4241bc2dc 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) @@ -983,6 +978,90 @@ static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) return 0; } +static u64 vsie_get_register(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, u8 reg) +{ + 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 = PAGE_MASK; + 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); + if (psw_bits(scb_s->gpsw).eaba == PSW_BITS_AMODE_24BIT) + mask = 0xfff000; + else if (psw_bits(scb_s->gpsw).eaba == PSW_BITS_AMODE_31BIT) + mask = 0x7ffff000; + + dest = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 16) & mask; + src = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 20) & mask; + + 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. beause 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 +1150,10 @@ 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; }
Correctly handle the MVPG instruction when issued by a VSIE guest. Fixes: a3508fbe9dc6d ("KVM: s390: vsie: initial support for nested virtualization") Cc: stable@vger.kernel.org Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> --- arch/s390/kvm/vsie.c | 93 +++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 88 insertions(+), 5 deletions(-)