Messages in this thread | | | Date | Tue, 14 Dec 2021 13:00:00 -0500 | Subject | Re: [PATCH 24/32] KVM: s390: intercept the rpcit instruction | From | Matthew Rosato <> |
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On 12/14/21 12:04 PM, Pierre Morel wrote: > > > On 12/7/21 21:57, Matthew Rosato wrote: >> For faster handling of PCI translation refreshes, intercept in KVM >> and call the associated handler. >> >> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com> >> --- >> arch/s390/kvm/pci.h | 4 ++++ >> arch/s390/kvm/priv.c | 41 +++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 45 insertions(+) >> >> diff --git a/arch/s390/kvm/pci.h b/arch/s390/kvm/pci.h >> index d252a631b693..3f96eff432aa 100644 >> --- a/arch/s390/kvm/pci.h >> +++ b/arch/s390/kvm/pci.h >> @@ -18,6 +18,10 @@ >> #define KVM_S390_PCI_DTSM_MASK 0x40 >> +#define KVM_S390_RPCIT_STAT_MASK 0xffffffff00ffffffUL >> +#define KVM_S390_RPCIT_INS_RES (0x10 << 24) >> +#define KVM_S390_RPCIT_ERR (0x28 << 24) > > I > >> + >> struct zpci_gaite { >> unsigned int gisa; >> u8 gisc; >> diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c >> index 417154b314a6..768ae92ecc59 100644 >> --- a/arch/s390/kvm/priv.c >> +++ b/arch/s390/kvm/priv.c >> @@ -29,6 +29,7 @@ >> #include <asm/ap.h> >> #include "gaccess.h" >> #include "kvm-s390.h" >> +#include "pci.h" >> #include "trace.h" >> static int handle_ri(struct kvm_vcpu *vcpu) >> @@ -335,6 +336,44 @@ static int handle_rrbe(struct kvm_vcpu *vcpu) >> return 0; >> } >> +static int handle_rpcit(struct kvm_vcpu *vcpu) >> +{ >> + int reg1, reg2; >> + int rc; >> + >> + if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) >> + return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); >> + >> + kvm_s390_get_regs_rre(vcpu, ®1, ®2); >> + > > I would prefer to take care of the interception immediately here > > fh = vcpu->run->s.regs.gprs[reg1] >> 32; > if ((fh & aift.mdd) != 0) > return -EOPNOTSUP > > instead of doing it inside kvm_s390_pci_refresh_trans. > It would simplify in my opinion.
OK
> >> + rc = kvm_s390_pci_refresh_trans(vcpu, vcpu->run->s.regs.gprs[reg1], >> + vcpu->run->s.regs.gprs[reg2], >> + vcpu->run->s.regs.gprs[reg2+1]); >> + > > >> + switch (rc) { >> + case 0: >> + kvm_s390_set_psw_cc(vcpu, 0); >> + break; >> + case -EOPNOTSUPP: >> + return -EOPNOTSUPP; >> + case -EINVAL: >> + kvm_s390_set_psw_cc(vcpu, 3); >> + break; >> + case -ENOMEM: >> + vcpu->run->s.regs.gprs[reg1] &= KVM_S390_RPCIT_STAT_MASK; >> + vcpu->run->s.regs.gprs[reg1] |= KVM_S390_RPCIT_INS_RES; >> + kvm_s390_set_psw_cc(vcpu, 1); >> + break; >> + default: >> + vcpu->run->s.regs.gprs[reg1] &= KVM_S390_RPCIT_STAT_MASK; >> + vcpu->run->s.regs.gprs[reg1] |= KVM_S390_RPCIT_ERR; > > I think you should use the status reported by the hardware, reporting > "Error recovery in progress" what ever the hardware error was does not > seem right. >
OK, this ties into your other comment about calling __rpcit() directly so we have a status to look at -- will look into it
>> + kvm_s390_set_psw_cc(vcpu, 1); >> + break; >> + } > > NIT: This switch above could be much more simple if you set CC after the > switch.
We are setting 3 different CCs over 4 cases, so there's only 1 duplication in the switch, so I'm not sure how much simpler?
But anyway this might not be relevant if I change to call __rpcit() directly.
> >> + >> + return 0; >> +} >> + >> #define SSKE_NQ 0x8 >> #define SSKE_MR 0x4 >> #define SSKE_MC 0x2 >> @@ -1275,6 +1314,8 @@ int kvm_s390_handle_b9(struct kvm_vcpu *vcpu) >> return handle_essa(vcpu); >> case 0xaf: >> return handle_pfmf(vcpu); >> + case 0xd3: >> + return handle_rpcit(vcpu); >> default: >> return -EOPNOTSUPP; >> } >> > > > > >
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