[PATCH v4 27/32] KVM: s390: intercept the rpcit instruction

[Matthew Rosato]

For faster handling of PCI translation refreshes, intercept in KVM
and call the associated handler.

Signed-off-by: Matthew Rosato <mjros...@linux.ibm.com>
---
 arch/s390/kvm/priv.c | 46 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 417154b314a6..546c99a0e0b6 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 +336,49 @@ 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 can only handle if we support KVM-managed IOMMU */
+       if (!IS_ENABLED(CONFIG_S390_KVM_IOMMU))
+               return -EOPNOTSUPP;
+
+       kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
+
+       /* If the device has a SHM bit on, let userspace take care of this */
+       if (((vcpu->run->s.regs.gprs[reg1] >> 32) & aift->mdd) != 0)
+               return -EOPNOTSUPP;
+
+       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 -ENOMEM:
+               vcpu->run->s.regs.gprs[reg1] &= 0xffffffff00ffffffUL;
+               vcpu->run->s.regs.gprs[reg1] |= (u64)4 << 24;
+               kvm_s390_set_psw_cc(vcpu, 1);
+               break;
+       case -EIO:
+               vcpu->run->s.regs.gprs[reg1] &= 0xffffffff00ffffffUL;
+               vcpu->run->s.regs.gprs[reg1] |= (u64)16 << 24;
+               kvm_s390_set_psw_cc(vcpu, 1);
+               break;
+       default:
+               kvm_s390_set_psw_cc(vcpu, 3);
+       }
+
+       return 0;
+}
+
 #define SSKE_NQ 0x8
 #define SSKE_MR 0x4
 #define SSKE_MC 0x2
@@ -1275,6 +1319,8 @@ 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;
        }
-- 
2.27.0

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