Merge tag 'pull-xenfv-stable-20231106' of git://git.infradead.org/users/dwmw2/qemu into staging
Bugfixes for emulated Xen support
Selected bugfixes for mainline and stable, especially to the per-vCPU
local APIC vector delivery mode for event channel notifications, which
was broken in a number of ways.
The xen-block driver has been defaulting to the wrong protocol for x86
guest, and this fixes that — which is technically an incompatible change
but I'm fairly sure nobody relies on the broken behaviour (and in
production I *have* seen guests which rely on the correct behaviour,
which now matches the blkback driver in the Linux kernel).
A handful of other simple fixes for issues which came to light as new
features (qv) were being developed.
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# gpg: Signature made Mon 06 Nov 2023 18:25:02 HKT
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# gpg: Good signature from "David Woodhouse <dwmw2@infradead.org>" [unknown]
# gpg: aka "David Woodhouse <dwmw2@exim.org>" [unknown]
# gpg: aka "David Woodhouse <david@woodhou.se>" [unknown]
# gpg: aka "David Woodhouse <dwmw2@kernel.org>" [unknown]
# gpg: WARNING: The key's User ID is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: BE07 D9FD 5480 9AB2 C4B0 FF5F 6376 2CDA 67E2 F359
* tag 'pull-xenfv-stable-20231106' of git://git.infradead.org/users/dwmw2/qemu:
hw/xen: use correct default protocol for xen-block on x86
hw/xen: take iothread mutex in xen_evtchn_reset_op()
hw/xen: fix XenStore watch delivery to guest
hw/xen: don't clear map_track[] in xen_gnttab_reset()
hw/xen: select kernel mode for per-vCPU event channel upcall vector
i386/xen: fix per-vCPU upcall vector for Xen emulation
i386/xen: Don't advertise XENFEAT_supervisor_mode_kernel
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c
index a07cd7e..bfa5396 100644
--- a/hw/block/xen-block.c
+++ b/hw/block/xen-block.c
@@ -115,9 +115,13 @@
return;
}
- if (xen_device_frontend_scanf(xendev, "protocol", "%ms",
- &str) != 1) {
- protocol = BLKIF_PROTOCOL_NATIVE;
+ if (xen_device_frontend_scanf(xendev, "protocol", "%ms", &str) != 1) {
+ /* x86 defaults to the 32-bit protocol even for 64-bit guests. */
+ if (object_dynamic_cast(OBJECT(qdev_get_machine()), "x86-machine")) {
+ protocol = BLKIF_PROTOCOL_X86_32;
+ } else {
+ protocol = BLKIF_PROTOCOL_NATIVE;
+ }
} else {
if (strcmp(str, XEN_IO_PROTO_ABI_X86_32) == 0) {
protocol = BLKIF_PROTOCOL_X86_32;
diff --git a/hw/i386/kvm/xen_evtchn.c b/hw/i386/kvm/xen_evtchn.c
index a731738..b2b4be9 100644
--- a/hw/i386/kvm/xen_evtchn.c
+++ b/hw/i386/kvm/xen_evtchn.c
@@ -490,6 +490,12 @@
break;
}
+ /* If the guest has set a per-vCPU callback vector, prefer that. */
+ if (gsi && kvm_xen_has_vcpu_callback_vector()) {
+ in_kernel = kvm_xen_has_cap(EVTCHN_SEND);
+ gsi = 0;
+ }
+
if (!ret) {
/* If vector delivery was turned *off* then tell the kernel */
if ((s->callback_param >> CALLBACK_VIA_TYPE_SHIFT) ==
@@ -1129,6 +1135,7 @@
return -ESRCH;
}
+ QEMU_IOTHREAD_LOCK_GUARD();
return xen_evtchn_soft_reset();
}
diff --git a/hw/i386/kvm/xen_gnttab.c b/hw/i386/kvm/xen_gnttab.c
index 21c30e3..839ec92 100644
--- a/hw/i386/kvm/xen_gnttab.c
+++ b/hw/i386/kvm/xen_gnttab.c
@@ -541,7 +541,5 @@
s->entries.v1[GNTTAB_RESERVED_XENSTORE].flags = GTF_permit_access;
s->entries.v1[GNTTAB_RESERVED_XENSTORE].frame = XEN_SPECIAL_PFN(XENSTORE);
- memset(s->map_track, 0, s->max_frames * ENTRIES_PER_FRAME_V1);
-
return 0;
}
diff --git a/hw/i386/kvm/xen_xenstore.c b/hw/i386/kvm/xen_xenstore.c
index 660d0b7..8e716a7 100644
--- a/hw/i386/kvm/xen_xenstore.c
+++ b/hw/i386/kvm/xen_xenstore.c
@@ -1357,10 +1357,12 @@
} else {
deliver_watch(s, path, token);
/*
- * If the message was queued because there was already ring activity,
- * no need to wake the guest. But if not, we need to send the evtchn.
+ * Attempt to queue the message into the actual ring, and send
+ * the event channel notification if any bytes are copied.
*/
- xen_be_evtchn_notify(s->eh, s->be_port);
+ if (s->rsp_pending && put_rsp(s) > 0) {
+ xen_be_evtchn_notify(s->eh, s->be_port);
+ }
}
}
diff --git a/include/sysemu/kvm_xen.h b/include/sysemu/kvm_xen.h
index 595abfb..961c702 100644
--- a/include/sysemu/kvm_xen.h
+++ b/include/sysemu/kvm_xen.h
@@ -22,6 +22,7 @@
int kvm_xen_soft_reset(void);
uint32_t kvm_xen_get_caps(void);
void *kvm_xen_get_vcpu_info_hva(uint32_t vcpu_id);
+bool kvm_xen_has_vcpu_callback_vector(void);
void kvm_xen_inject_vcpu_callback_vector(uint32_t vcpu_id, int type);
void kvm_xen_set_callback_asserted(void);
int kvm_xen_set_vcpu_virq(uint32_t vcpu_id, uint16_t virq, uint16_t port);
diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
index 76348f9..75b2c55 100644
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -267,7 +267,6 @@
fi.submap |= 1 << XENFEAT_writable_page_tables |
1 << XENFEAT_writable_descriptor_tables |
1 << XENFEAT_auto_translated_physmap |
- 1 << XENFEAT_supervisor_mode_kernel |
1 << XENFEAT_hvm_callback_vector |
1 << XENFEAT_hvm_safe_pvclock |
1 << XENFEAT_hvm_pirqs;
@@ -307,7 +306,7 @@
trace_kvm_xen_set_vcpu_callback(cs->cpu_index, vector);
- return kvm_vcpu_ioctl(cs, KVM_XEN_HVM_SET_ATTR, &xva);
+ return kvm_vcpu_ioctl(cs, KVM_XEN_VCPU_SET_ATTR, &xva);
}
static void do_set_vcpu_callback_vector(CPUState *cs, run_on_cpu_data data)
@@ -425,6 +424,13 @@
}
}
+bool kvm_xen_has_vcpu_callback_vector(void)
+{
+ CPUState *cs = qemu_get_cpu(0);
+
+ return cs && !!X86_CPU(cs)->env.xen_vcpu_callback_vector;
+}
+
void kvm_xen_inject_vcpu_callback_vector(uint32_t vcpu_id, int type)
{
CPUState *cs = qemu_get_cpu(vcpu_id);
@@ -441,7 +447,8 @@
* deliver it as an MSI.
*/
MSIMessage msg = {
- .address = APIC_DEFAULT_ADDRESS | X86_CPU(cs)->apic_id,
+ .address = APIC_DEFAULT_ADDRESS |
+ (X86_CPU(cs)->apic_id << MSI_ADDR_DEST_ID_SHIFT),
.data = vector | (1UL << MSI_DATA_LEVEL_SHIFT),
};
kvm_irqchip_send_msi(kvm_state, msg);
@@ -850,8 +857,7 @@
int ret = -ENOSYS;
switch (cmd) {
case HVMOP_set_evtchn_upcall_vector:
- ret = kvm_xen_hcall_evtchn_upcall_vector(exit, cpu,
- exit->u.hcall.params[0]);
+ ret = kvm_xen_hcall_evtchn_upcall_vector(exit, cpu, arg);
break;
case HVMOP_pagetable_dying:
