From 2f7c68cb55ecb7331f2381deb497c27155f32faf Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 03 Jan 2024 09:43:39 +0000
Subject: [PATCH] update kernel to 5.10.198
---
kernel/arch/s390/kvm/intercept.c | 41 ++++++++++++++++++++++++++++++-----------
1 files changed, 30 insertions(+), 11 deletions(-)
diff --git a/kernel/arch/s390/kvm/intercept.c b/kernel/arch/s390/kvm/intercept.c
index 77909d3..8bf72a3 100644
--- a/kernel/arch/s390/kvm/intercept.c
+++ b/kernel/arch/s390/kvm/intercept.c
@@ -270,10 +270,18 @@
/**
* handle_external_interrupt - used for external interruption interceptions
*
- * 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.
+ * 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.
+ *
+ * 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)
{
@@ -284,10 +292,18 @@
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;
@@ -371,8 +387,8 @@
*/
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))
@@ -403,7 +419,10 @@
return -ENOMEM;
cc = sthyi_fill(sctns, &rc);
-
+ if (cc < 0) {
+ free_page((unsigned long)sctns);
+ return cc;
+ }
out:
if (!cc) {
if (kvm_s390_pv_cpu_is_protected(vcpu)) {
--
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