svn commit: r354637 - head/sys/x86/xen
Roger Pau Monné
royger at FreeBSD.org
Tue Nov 12 10:31:29 UTC 2019
Author: royger
Date: Tue Nov 12 10:31:28 2019
New Revision: 354637
URL: https://svnweb.freebsd.org/changeset/base/354637
Log:
xen: fix dispatching of NMIs
Currently NMIs are sent over event channels, but that defeats the
purpose of NMIs since event channels can be masked. Fix this by
issuing NMIs using a hypercall, which injects a NMI (vector #2) to the
desired vCPU.
Note that NMIs could also be triggered using the emulated local APIC,
but using a hypercall is better from a performance point of view
since it doesn't involve instruction decoding when not using x2APIC
mode.
Reported and Tested by: avg
Sponsored by: Citrix Systems R&D
Modified:
head/sys/x86/xen/xen_apic.c
Modified: head/sys/x86/xen/xen_apic.c
==============================================================================
--- head/sys/x86/xen/xen_apic.c Tue Nov 12 10:22:48 2019 (r354636)
+++ head/sys/x86/xen/xen_apic.c Tue Nov 12 10:31:28 2019 (r354637)
@@ -72,7 +72,6 @@ static driver_filter_t xen_invlcache;
static driver_filter_t xen_ipi_bitmap_handler;
static driver_filter_t xen_cpustop_handler;
static driver_filter_t xen_cpususpend_handler;
-static driver_filter_t xen_cpustophard_handler;
#endif
/*---------------------------------- Macros ----------------------------------*/
@@ -96,7 +95,6 @@ static struct xen_ipi_handler xen_ipis[] =
[IPI_TO_IDX(IPI_BITMAP_VECTOR)] = { xen_ipi_bitmap_handler, "b" },
[IPI_TO_IDX(IPI_STOP)] = { xen_cpustop_handler, "st" },
[IPI_TO_IDX(IPI_SUSPEND)] = { xen_cpususpend_handler, "sp" },
- [IPI_TO_IDX(IPI_STOP_HARD)] = { xen_cpustophard_handler, "sth" },
};
#endif
@@ -259,12 +257,52 @@ xen_pv_lapic_ipi_raw(register_t icrlo, u_int dest)
XEN_APIC_UNSUPPORTED;
}
+#define PCPU_ID_GET(id, field) (pcpu_find(id)->pc_##field)
static void
+send_nmi(int dest)
+{
+ unsigned int cpu;
+
+ /*
+ * NMIs are not routed over event channels, and instead delivered as on
+ * native using the exception vector (#2). Triggering them can be done
+ * using the local APIC, or an hypercall as a shortcut like it's done
+ * below.
+ */
+ switch(dest) {
+ case APIC_IPI_DEST_SELF:
+ HYPERVISOR_vcpu_op(VCPUOP_send_nmi, PCPU_GET(vcpu_id), NULL);
+ break;
+ case APIC_IPI_DEST_ALL:
+ CPU_FOREACH(cpu)
+ HYPERVISOR_vcpu_op(VCPUOP_send_nmi,
+ PCPU_ID_GET(cpu, vcpu_id), NULL);
+ break;
+ case APIC_IPI_DEST_OTHERS:
+ CPU_FOREACH(cpu)
+ if (cpu != PCPU_GET(cpuid))
+ HYPERVISOR_vcpu_op(VCPUOP_send_nmi,
+ PCPU_ID_GET(cpu, vcpu_id), NULL);
+ break;
+ default:
+ HYPERVISOR_vcpu_op(VCPUOP_send_nmi,
+ PCPU_ID_GET(apic_cpuid(dest), vcpu_id), NULL);
+ break;
+ }
+}
+#undef PCPU_ID_GET
+
+static void
xen_pv_lapic_ipi_vectored(u_int vector, int dest)
{
xen_intr_handle_t *ipi_handle;
int ipi_idx, to_cpu, self;
+ if (vector >= IPI_NMI_FIRST) {
+ send_nmi(dest);
+ return;
+ }
+
ipi_idx = IPI_TO_IDX(vector);
if (ipi_idx >= nitems(xen_ipis))
panic("IPI out of range");
@@ -519,14 +557,6 @@ xen_cpususpend_handler(void *arg)
{
cpususpend_handler();
- return (FILTER_HANDLED);
-}
-
-static int
-xen_cpustophard_handler(void *arg)
-{
-
- ipi_nmi_handler();
return (FILTER_HANDLED);
}
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