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Diffstat (limited to 'arch/s390/kvm/intercept.c')
-rw-r--r--arch/s390/kvm/intercept.c246
1 files changed, 211 insertions, 35 deletions
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index a389fa85cca2..420ae62977e2 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -2,7 +2,7 @@
/*
* in-kernel handling for sie intercepts
*
- * Copyright IBM Corp. 2008, 2014
+ * Copyright IBM Corp. 2008, 2020
*
* Author(s): Carsten Otte <cotte@de.ibm.com>
* Christian Borntraeger <borntraeger@de.ibm.com>
@@ -12,10 +12,10 @@
#include <linux/errno.h>
#include <linux/pagemap.h>
-#include <asm/kvm_host.h>
#include <asm/asm-offsets.h>
#include <asm/irq.h>
#include <asm/sysinfo.h>
+#include <asm/uv.h>
#include "kvm-s390.h"
#include "gaccess.h"
@@ -79,6 +79,10 @@ static int handle_stop(struct kvm_vcpu *vcpu)
return rc;
}
+ /*
+ * 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);
return -EOPNOTSUPP;
@@ -90,7 +94,7 @@ static int handle_validity(struct kvm_vcpu *vcpu)
vcpu->stat.exit_validity++;
trace_kvm_s390_intercept_validity(vcpu, viwhy);
- KVM_EVENT(3, "validity intercept 0x%x for pid %u (kvm 0x%pK)", viwhy,
+ KVM_EVENT(3, "validity intercept 0x%x for pid %u (kvm 0x%p)", viwhy,
current->pid, vcpu->kvm);
/* do not warn on invalid runtime instrumentation mode */
@@ -213,7 +217,7 @@ static int handle_itdb(struct kvm_vcpu *vcpu)
return 0;
if (current->thread.per_flags & PER_FLAG_NO_TE)
return 0;
- itdb = (struct kvm_s390_itdb *)vcpu->arch.sie_block->itdba;
+ itdb = phys_to_virt(vcpu->arch.sie_block->itdba);
rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
if (rc)
return rc;
@@ -224,6 +228,21 @@ static int handle_itdb(struct kvm_vcpu *vcpu)
#define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
+static bool should_handle_per_event(const struct kvm_vcpu *vcpu)
+{
+ if (!guestdbg_enabled(vcpu) || !per_event(vcpu))
+ return false;
+ if (guestdbg_sstep_enabled(vcpu) &&
+ vcpu->arch.sie_block->iprcc != PGM_PER) {
+ /*
+ * __vcpu_run() will exit after delivering the concurrently
+ * indicated condition.
+ */
+ return false;
+ }
+ return true;
+}
+
static int handle_prog(struct kvm_vcpu *vcpu)
{
psw_t psw;
@@ -231,7 +250,14 @@ static int handle_prog(struct kvm_vcpu *vcpu)
vcpu->stat.exit_program_interruption++;
- if (guestdbg_enabled(vcpu) && per_event(vcpu)) {
+ /*
+ * Intercept 8 indicates a loop of specification exceptions
+ * for protected guests.
+ */
+ if (kvm_s390_pv_cpu_is_protected(vcpu))
+ return -EOPNOTSUPP;
+
+ if (should_handle_per_event(vcpu)) {
rc = kvm_s390_handle_per_event(vcpu);
if (rc)
return rc;
@@ -258,11 +284,20 @@ static int handle_prog(struct kvm_vcpu *vcpu)
/**
* handle_external_interrupt - used for external interruption interceptions
+ * @vcpu: virtual cpu
+ *
+ * This interception occurs if:
+ * - the CPUSTAT_EXT_INT bit was already set when the external interrupt
+ * occurred. In this case, the interrupt needs to be injected manually to
+ * preserve interrupt priority.
+ * - the external new PSW has external interrupts enabled, which will cause an
+ * interruption loop. We drop to userspace in this case.
+ *
+ * The latter case can be detected by inspecting the external mask bit in the
+ * external new psw.
*
- * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
- * the new PSW does not have external interrupts disabled. In the first case,
- * we've got to deliver the interrupt manually, and in the second case, we
- * drop to userspace to handle the situation there.
+ * Under PV, only the latter case can occur, since interrupt priorities are
+ * handled in the ultravisor.
*/
static int handle_external_interrupt(struct kvm_vcpu *vcpu)
{
@@ -273,10 +308,18 @@ static int handle_external_interrupt(struct kvm_vcpu *vcpu)
vcpu->stat.exit_external_interrupt++;
- rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
- if (rc)
- return rc;
- /* We can not handle clock comparator or timer interrupt with bad PSW */
+ if (kvm_s390_pv_cpu_is_protected(vcpu)) {
+ newpsw = vcpu->arch.sie_block->gpsw;
+ } else {
+ rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
+ if (rc)
+ return rc;
+ }
+
+ /*
+ * Clock comparator or timer interrupt with external interrupt enabled
+ * will cause interrupt loop. Drop to userspace.
+ */
if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
(newpsw.mask & PSW_MASK_EXT))
return -EOPNOTSUPP;
@@ -304,7 +347,8 @@ static int handle_external_interrupt(struct kvm_vcpu *vcpu)
}
/**
- * Handle MOVE PAGE partial execution interception.
+ * handle_mvpg_pei - Handle MOVE PAGE partial execution interception.
+ * @vcpu: virtual cpu
*
* This interception can only happen for guests with DAT disabled and
* addresses that are currently not mapped in the host. Thus we try to
@@ -318,21 +362,21 @@ static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
- /* Make sure that the source is paged-in */
- rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg2],
- reg2, &srcaddr, GACC_FETCH);
+ /* Ensure that the source is paged-in, no actual access -> no key checking */
+ rc = guest_translate_address_with_key(vcpu, vcpu->run->s.regs.gprs[reg2],
+ reg2, &srcaddr, GACC_FETCH, 0);
if (rc)
return kvm_s390_inject_prog_cond(vcpu, rc);
- rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
+ rc = kvm_s390_handle_dat_fault(vcpu, srcaddr, 0);
if (rc != 0)
return rc;
- /* Make sure that the destination is paged-in */
- rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg1],
- reg1, &dstaddr, GACC_STORE);
+ /* Ensure that the source is paged-in, no actual access -> no key checking */
+ rc = guest_translate_address_with_key(vcpu, vcpu->run->s.regs.gprs[reg1],
+ reg1, &dstaddr, GACC_STORE, 0);
if (rc)
return kvm_s390_inject_prog_cond(vcpu, rc);
- rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
+ rc = kvm_s390_handle_dat_fault(vcpu, dstaddr, FOLL_WRITE);
if (rc != 0)
return rc;
@@ -360,8 +404,8 @@ static int handle_partial_execution(struct kvm_vcpu *vcpu)
*/
int handle_sthyi(struct kvm_vcpu *vcpu)
{
- int reg1, reg2, r = 0;
- u64 code, addr, cc = 0, rc = 0;
+ int reg1, reg2, cc = 0, r = 0;
+ u64 code, addr, rc = 0;
struct sthyi_sctns *sctns = NULL;
if (!test_kvm_facility(vcpu->kvm, 74))
@@ -384,21 +428,28 @@ int handle_sthyi(struct kvm_vcpu *vcpu)
goto out;
}
- if (addr & ~PAGE_MASK)
+ if (!kvm_s390_pv_cpu_is_protected(vcpu) && (addr & ~PAGE_MASK))
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
- sctns = (void *)get_zeroed_page(GFP_KERNEL);
+ sctns = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
if (!sctns)
return -ENOMEM;
cc = sthyi_fill(sctns, &rc);
-
+ if (cc < 0) {
+ free_page((unsigned long)sctns);
+ return cc;
+ }
out:
if (!cc) {
- r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);
- if (r) {
- free_page((unsigned long)sctns);
- return kvm_s390_inject_prog_cond(vcpu, r);
+ if (kvm_s390_pv_cpu_is_protected(vcpu)) {
+ memcpy(sida_addr(vcpu->arch.sie_block), sctns, PAGE_SIZE);
+ } else {
+ r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);
+ if (r) {
+ free_page((unsigned long)sctns);
+ return kvm_s390_inject_prog_cond(vcpu, r);
+ }
}
}
@@ -420,6 +471,9 @@ static int handle_operexc(struct kvm_vcpu *vcpu)
if (vcpu->arch.sie_block->ipa == 0xb256)
return handle_sthyi(vcpu);
+ if (vcpu->kvm->arch.user_operexec)
+ return -EOPNOTSUPP;
+
if (vcpu->arch.sie_block->ipa == 0 && vcpu->kvm->arch.user_instr0)
return -EOPNOTSUPP;
rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &newpsw, sizeof(psw_t));
@@ -444,6 +498,110 @@ static int handle_operexc(struct kvm_vcpu *vcpu)
return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
}
+static int handle_pv_spx(struct kvm_vcpu *vcpu)
+{
+ u32 pref = *(u32 *)sida_addr(vcpu->arch.sie_block);
+
+ kvm_s390_set_prefix(vcpu, pref);
+ trace_kvm_s390_handle_prefix(vcpu, 1, pref);
+ return 0;
+}
+
+static int handle_pv_sclp(struct kvm_vcpu *vcpu)
+{
+ struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
+
+ spin_lock(&fi->lock);
+ /*
+ * 2 cases:
+ * a: an sccb answering interrupt was already pending or in flight.
+ * As the sccb value is not known we can simply set some value to
+ * trigger delivery of a saved SCCB. UV will then use its saved
+ * copy of the SCCB value.
+ * b: an error SCCB interrupt needs to be injected so we also inject
+ * a fake SCCB address. Firmware will use the proper one.
+ * This makes sure, that both errors and real sccb returns will only
+ * be delivered after a notification intercept (instruction has
+ * finished) but not after others.
+ */
+ fi->srv_signal.ext_params |= 0x43000;
+ set_bit(IRQ_PEND_EXT_SERVICE, &fi->pending_irqs);
+ clear_bit(IRQ_PEND_EXT_SERVICE, &fi->masked_irqs);
+ spin_unlock(&fi->lock);
+ return 0;
+}
+
+static int handle_pv_uvc(struct kvm_vcpu *vcpu)
+{
+ struct uv_cb_share *guest_uvcb = sida_addr(vcpu->arch.sie_block);
+ struct uv_cb_cts uvcb = {
+ .header.cmd = UVC_CMD_UNPIN_PAGE_SHARED,
+ .header.len = sizeof(uvcb),
+ .guest_handle = kvm_s390_pv_get_handle(vcpu->kvm),
+ .gaddr = guest_uvcb->paddr,
+ };
+ int rc;
+
+ if (guest_uvcb->header.cmd != UVC_CMD_REMOVE_SHARED_ACCESS) {
+ WARN_ONCE(1, "Unexpected notification intercept for UVC 0x%x\n",
+ guest_uvcb->header.cmd);
+ return 0;
+ }
+ rc = kvm_s390_pv_make_secure(vcpu->kvm, uvcb.gaddr, &uvcb);
+ /*
+ * If the unpin did not succeed, the guest will exit again for the UVC
+ * and we will retry the unpin.
+ */
+ if (rc == -EINVAL || rc == -ENXIO)
+ return 0;
+ /*
+ * If we got -EAGAIN here, we simply return it. It will eventually
+ * get propagated all the way to userspace, which should then try
+ * again.
+ */
+ return rc;
+}
+
+static int handle_pv_notification(struct kvm_vcpu *vcpu)
+{
+ int ret;
+
+ if (vcpu->arch.sie_block->ipa == 0xb210)
+ return handle_pv_spx(vcpu);
+ if (vcpu->arch.sie_block->ipa == 0xb220)
+ return handle_pv_sclp(vcpu);
+ if (vcpu->arch.sie_block->ipa == 0xb9a4)
+ return handle_pv_uvc(vcpu);
+ if (vcpu->arch.sie_block->ipa >> 8 == 0xae) {
+ /*
+ * Besides external call, other SIGP orders also cause a
+ * 108 (pv notify) intercept. In contrast to external call,
+ * these orders need to be emulated and hence the appropriate
+ * place to handle them is in handle_instruction().
+ * So first try kvm_s390_handle_sigp_pei() and if that isn't
+ * successful, go on with handle_instruction().
+ */
+ ret = kvm_s390_handle_sigp_pei(vcpu);
+ if (!ret)
+ return ret;
+ }
+
+ return handle_instruction(vcpu);
+}
+
+static bool should_handle_per_ifetch(const struct kvm_vcpu *vcpu, int rc)
+{
+ /* Process PER, also if the instruction is processed in user space. */
+ if (!(vcpu->arch.sie_block->icptstatus & 0x02))
+ return false;
+ if (rc != 0 && rc != -EOPNOTSUPP)
+ return false;
+ if (guestdbg_sstep_enabled(vcpu) && vcpu->arch.local_int.pending_irqs)
+ /* __vcpu_run() will exit after delivering the interrupt. */
+ return false;
+ return true;
+}
+
int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
{
int rc, per_rc = 0;
@@ -478,15 +636,33 @@ int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
rc = handle_partial_execution(vcpu);
break;
case ICPT_KSS:
- rc = kvm_s390_skey_check_enable(vcpu);
+ /* Instruction will be redriven, skip the PER check. */
+ return kvm_s390_skey_check_enable(vcpu);
+ case ICPT_MCHKREQ:
+ case ICPT_INT_ENABLE:
+ /*
+ * PSW bit 13 or a CR (0, 6, 14) changed and we might
+ * now be able to deliver interrupts. The pre-run code
+ * will take care of this.
+ */
+ rc = 0;
+ break;
+ case ICPT_PV_INSTR:
+ rc = handle_instruction(vcpu);
+ break;
+ case ICPT_PV_NOTIFY:
+ rc = handle_pv_notification(vcpu);
+ break;
+ case ICPT_PV_PREF:
+ rc = 0;
+ kvm_s390_pv_convert_to_secure(vcpu->kvm, kvm_s390_get_prefix(vcpu));
+ kvm_s390_pv_convert_to_secure(vcpu->kvm, kvm_s390_get_prefix(vcpu) + PAGE_SIZE);
break;
default:
return -EOPNOTSUPP;
}
- /* process PER, also if the instrution is processed in user space */
- if (vcpu->arch.sie_block->icptstatus & 0x02 &&
- (!rc || rc == -EOPNOTSUPP))
+ if (should_handle_per_ifetch(vcpu, rc))
per_rc = kvm_s390_handle_per_ifetch_icpt(vcpu);
return per_rc ? per_rc : rc;
}
generated by cgit (git 2.34.1) at 2025-12-24 22:50:05 +0000