2022-03-14 20:31:33

by Matthew Rosato

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

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

Signed-off-by: Matthew Rosato <[email protected]>
---
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