Re: [PATCH 24/32] KVM: s390: intercept the rpcit instruction
From: Pierre Morel <hidden>
Date: 2021-12-14 17:03:08
Also in:
kvm, lkml
On 12/7/21 21:57, Matthew Rosato wrote:
quoted hunk ↗ jump to hunk
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
quoted hunk ↗ jump to hunk
+ 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.
+ 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.
+ kvm_s390_set_psw_cc(vcpu, 1); + break; + }
NIT: This switch above could be much more simple if you set CC after the switch.
quoted hunk ↗ jump to hunk
+ + 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; }
-- Pierre Morel IBM Lab Boeblingen