summaryrefslogtreecommitdiffstats
path: root/arch/s390/kvm/diag.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/s390/kvm/diag.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/s390/kvm/diag.c')
-rw-r--r--arch/s390/kvm/diag.c307
1 files changed, 307 insertions, 0 deletions
diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
new file mode 100644
index 000000000..3c65b8258
--- /dev/null
+++ b/arch/s390/kvm/diag.c
@@ -0,0 +1,307 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * handling diagnose instructions
+ *
+ * Copyright IBM Corp. 2008, 2020
+ *
+ * Author(s): Carsten Otte <cotte@de.ibm.com>
+ * Christian Borntraeger <borntraeger@de.ibm.com>
+ */
+
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <asm/gmap.h>
+#include <asm/virtio-ccw.h>
+#include "kvm-s390.h"
+#include "trace.h"
+#include "trace-s390.h"
+#include "gaccess.h"
+
+static int diag_release_pages(struct kvm_vcpu *vcpu)
+{
+ unsigned long start, end;
+ unsigned long prefix = kvm_s390_get_prefix(vcpu);
+
+ start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
+ end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + PAGE_SIZE;
+ vcpu->stat.instruction_diagnose_10++;
+
+ if (start & ~PAGE_MASK || end & ~PAGE_MASK || start >= end
+ || start < 2 * PAGE_SIZE)
+ return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+
+ VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
+
+ /*
+ * We checked for start >= end above, so lets check for the
+ * fast path (no prefix swap page involved)
+ */
+ if (end <= prefix || start >= prefix + 2 * PAGE_SIZE) {
+ gmap_discard(vcpu->arch.gmap, start, end);
+ } else {
+ /*
+ * This is slow path. gmap_discard will check for start
+ * so lets split this into before prefix, prefix, after
+ * prefix and let gmap_discard make some of these calls
+ * NOPs.
+ */
+ gmap_discard(vcpu->arch.gmap, start, prefix);
+ if (start <= prefix)
+ gmap_discard(vcpu->arch.gmap, 0, PAGE_SIZE);
+ if (end > prefix + PAGE_SIZE)
+ gmap_discard(vcpu->arch.gmap, PAGE_SIZE, 2 * PAGE_SIZE);
+ gmap_discard(vcpu->arch.gmap, prefix + 2 * PAGE_SIZE, end);
+ }
+ return 0;
+}
+
+static int __diag_page_ref_service(struct kvm_vcpu *vcpu)
+{
+ struct prs_parm {
+ u16 code;
+ u16 subcode;
+ u16 parm_len;
+ u16 parm_version;
+ u64 token_addr;
+ u64 select_mask;
+ u64 compare_mask;
+ u64 zarch;
+ };
+ struct prs_parm parm;
+ int rc;
+ u16 rx = (vcpu->arch.sie_block->ipa & 0xf0) >> 4;
+ u16 ry = (vcpu->arch.sie_block->ipa & 0x0f);
+
+ VCPU_EVENT(vcpu, 3, "diag page reference parameter block at 0x%llx",
+ vcpu->run->s.regs.gprs[rx]);
+ vcpu->stat.instruction_diagnose_258++;
+ if (vcpu->run->s.regs.gprs[rx] & 7)
+ return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+ rc = read_guest(vcpu, vcpu->run->s.regs.gprs[rx], rx, &parm, sizeof(parm));
+ if (rc)
+ return kvm_s390_inject_prog_cond(vcpu, rc);
+ if (parm.parm_version != 2 || parm.parm_len < 5 || parm.code != 0x258)
+ return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+
+ switch (parm.subcode) {
+ case 0: /* TOKEN */
+ VCPU_EVENT(vcpu, 3, "pageref token addr 0x%llx "
+ "select mask 0x%llx compare mask 0x%llx",
+ parm.token_addr, parm.select_mask, parm.compare_mask);
+ if (vcpu->arch.pfault_token != KVM_S390_PFAULT_TOKEN_INVALID) {
+ /*
+ * If the pagefault handshake is already activated,
+ * the token must not be changed. We have to return
+ * decimal 8 instead, as mandated in SC24-6084.
+ */
+ vcpu->run->s.regs.gprs[ry] = 8;
+ return 0;
+ }
+
+ if ((parm.compare_mask & parm.select_mask) != parm.compare_mask ||
+ parm.token_addr & 7 || parm.zarch != 0x8000000000000000ULL)
+ return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+
+ if (kvm_is_error_gpa(vcpu->kvm, parm.token_addr))
+ return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+
+ vcpu->arch.pfault_token = parm.token_addr;
+ vcpu->arch.pfault_select = parm.select_mask;
+ vcpu->arch.pfault_compare = parm.compare_mask;
+ vcpu->run->s.regs.gprs[ry] = 0;
+ rc = 0;
+ break;
+ case 1: /*
+ * CANCEL
+ * Specification allows to let already pending tokens survive
+ * the cancel, therefore to reduce code complexity, we assume
+ * all outstanding tokens are already pending.
+ */
+ VCPU_EVENT(vcpu, 3, "pageref cancel addr 0x%llx", parm.token_addr);
+ if (parm.token_addr || parm.select_mask ||
+ parm.compare_mask || parm.zarch)
+ return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+
+ vcpu->run->s.regs.gprs[ry] = 0;
+ /*
+ * If the pfault handling was not established or is already
+ * canceled SC24-6084 requests to return decimal 4.
+ */
+ if (vcpu->arch.pfault_token == KVM_S390_PFAULT_TOKEN_INVALID)
+ vcpu->run->s.regs.gprs[ry] = 4;
+ else
+ vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
+
+ rc = 0;
+ break;
+ default:
+ rc = -EOPNOTSUPP;
+ break;
+ }
+
+ return rc;
+}
+
+static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
+{
+ VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
+ vcpu->stat.instruction_diagnose_44++;
+ kvm_vcpu_on_spin(vcpu, true);
+ return 0;
+}
+
+static int forward_cnt;
+static unsigned long cur_slice;
+
+static int diag9c_forwarding_overrun(void)
+{
+ /* Reset the count on a new slice */
+ if (time_after(jiffies, cur_slice)) {
+ cur_slice = jiffies;
+ forward_cnt = diag9c_forwarding_hz / HZ;
+ }
+ return forward_cnt-- <= 0 ? 1 : 0;
+}
+
+static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
+{
+ struct kvm_vcpu *tcpu;
+ int tcpu_cpu;
+ int tid;
+
+ tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
+ vcpu->stat.instruction_diagnose_9c++;
+
+ /* yield to self */
+ if (tid == vcpu->vcpu_id)
+ goto no_yield;
+
+ /* yield to invalid */
+ tcpu = kvm_get_vcpu_by_id(vcpu->kvm, tid);
+ if (!tcpu)
+ goto no_yield;
+
+ /* target guest VCPU already running */
+ tcpu_cpu = READ_ONCE(tcpu->cpu);
+ if (tcpu_cpu >= 0) {
+ if (!diag9c_forwarding_hz || diag9c_forwarding_overrun())
+ goto no_yield;
+
+ /* target host CPU already running */
+ if (!vcpu_is_preempted(tcpu_cpu))
+ goto no_yield;
+ smp_yield_cpu(tcpu_cpu);
+ VCPU_EVENT(vcpu, 5,
+ "diag time slice end directed to %d: yield forwarded",
+ tid);
+ vcpu->stat.diag_9c_forward++;
+ return 0;
+ }
+
+ if (kvm_vcpu_yield_to(tcpu) <= 0)
+ goto no_yield;
+
+ VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d: done", tid);
+ return 0;
+no_yield:
+ VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d: ignored", tid);
+ vcpu->stat.diag_9c_ignored++;
+ return 0;
+}
+
+static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
+{
+ unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
+ unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
+
+ VCPU_EVENT(vcpu, 3, "diag ipl functions, subcode %lx", subcode);
+ vcpu->stat.instruction_diagnose_308++;
+ switch (subcode) {
+ case 3:
+ vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
+ break;
+ case 4:
+ vcpu->run->s390_reset_flags = 0;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ /*
+ * no need to check the return value of vcpu_stop as it can only have
+ * an error for protvirt, but protvirt means user cpu state
+ */
+ if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
+ kvm_s390_vcpu_stop(vcpu);
+ vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
+ vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
+ vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
+ vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
+ VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
+ vcpu->run->s390_reset_flags);
+ trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags);
+ return -EREMOTE;
+}
+
+static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
+{
+ int ret;
+
+ vcpu->stat.instruction_diagnose_500++;
+ /* No virtio-ccw notification? Get out quickly. */
+ if (!vcpu->kvm->arch.css_support ||
+ (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
+ return -EOPNOTSUPP;
+
+ VCPU_EVENT(vcpu, 4, "diag 0x500 schid 0x%8.8x queue 0x%x cookie 0x%llx",
+ (u32) vcpu->run->s.regs.gprs[2],
+ (u32) vcpu->run->s.regs.gprs[3],
+ vcpu->run->s.regs.gprs[4]);
+
+ /*
+ * The layout is as follows:
+ * - gpr 2 contains the subchannel id (passed as addr)
+ * - gpr 3 contains the virtqueue index (passed as datamatch)
+ * - gpr 4 contains the index on the bus (optionally)
+ */
+ ret = kvm_io_bus_write_cookie(vcpu, KVM_VIRTIO_CCW_NOTIFY_BUS,
+ vcpu->run->s.regs.gprs[2] & 0xffffffff,
+ 8, &vcpu->run->s.regs.gprs[3],
+ vcpu->run->s.regs.gprs[4]);
+
+ /*
+ * Return cookie in gpr 2, but don't overwrite the register if the
+ * diagnose will be handled by userspace.
+ */
+ if (ret != -EOPNOTSUPP)
+ vcpu->run->s.regs.gprs[2] = ret;
+ /* kvm_io_bus_write_cookie returns -EOPNOTSUPP if it found no match. */
+ return ret < 0 ? ret : 0;
+}
+
+int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
+{
+ int code = kvm_s390_get_base_disp_rs(vcpu, NULL) & 0xffff;
+
+ if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
+ return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
+
+ trace_kvm_s390_handle_diag(vcpu, code);
+ switch (code) {
+ case 0x10:
+ return diag_release_pages(vcpu);
+ case 0x44:
+ return __diag_time_slice_end(vcpu);
+ case 0x9c:
+ return __diag_time_slice_end_directed(vcpu);
+ case 0x258:
+ return __diag_page_ref_service(vcpu);
+ case 0x308:
+ return __diag_ipl_functions(vcpu);
+ case 0x500:
+ return __diag_virtio_hypercall(vcpu);
+ default:
+ vcpu->stat.instruction_diagnose_other++;
+ return -EOPNOTSUPP;
+ }
+}