/*
* Copyright (c) 2014 Roger Pau Monné <roger.pau@citrix.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/smp.h>
#include <sys/systm.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <machine/cpufunc.h>
#include <machine/cpu.h>
#include <machine/intr_machdep.h>
#include <machine/md_var.h>
#include <machine/smp.h>
#include <x86/apicreg.h>
#include <x86/apicvar.h>
#include <xen/xen-os.h>
#include <xen/features.h>
#include <xen/gnttab.h>
#include <xen/hypervisor.h>
#include <xen/hvm.h>
#include <xen/xen_intr.h>
#include <contrib/xen/arch-x86/cpuid.h>
#include <contrib/xen/vcpu.h>
/*--------------------------- Forward Declarations ---------------------------*/
static driver_filter_t xen_smp_rendezvous_action;
#ifdef __amd64__
static driver_filter_t xen_invlop;
#else
static driver_filter_t xen_invltlb;
static driver_filter_t xen_invlpg;
static driver_filter_t xen_invlrng;
static driver_filter_t xen_invlcache;
#endif
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_ipi_swi_handler;
/*---------------------------------- Macros ----------------------------------*/
#define IPI_TO_IDX(ipi) ((ipi) - APIC_IPI_INTS)
/*--------------------------------- Xen IPIs ---------------------------------*/
struct xen_ipi_handler
{
driver_filter_t *filter;
const char *description;
};
static struct xen_ipi_handler xen_ipis[] =
{
[IPI_TO_IDX(IPI_RENDEZVOUS)] = { xen_smp_rendezvous_action, "r" },
#ifdef __amd64__
[IPI_TO_IDX(IPI_INVLOP)] = { xen_invlop, "itlb"},
#else
[IPI_TO_IDX(IPI_INVLTLB)] = { xen_invltlb, "itlb"},
[IPI_TO_IDX(IPI_INVLPG)] = { xen_invlpg, "ipg" },
[IPI_TO_IDX(IPI_INVLRNG)] = { xen_invlrng, "irg" },
[IPI_TO_IDX(IPI_INVLCACHE)] = { xen_invlcache, "ic" },
#endif
[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_SWI)] = { xen_ipi_swi_handler, "sw" },
};
/*
* Save previous (native) handler as a fallback. Xen < 4.7 doesn't support
* VCPUOP_send_nmi for HVM guests, and thus we need a fallback in that case:
*
* https://lists.freebsd.org/archives/freebsd-xen/2022-January/000032.html
*/
void (*native_ipi_vectored)(u_int, int);
/*------------------------------- Per-CPU Data -------------------------------*/
DPCPU_DEFINE(xen_intr_handle_t, ipi_handle[nitems(xen_ipis)]);
/*------------------------------- Xen PV APIC --------------------------------*/
#define PCPU_ID_GET(id, field) (pcpu_find(id)->pc_##field)
static int
send_nmi(int dest)
{
unsigned int cpu;
int rc = 0;
/*
* 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:
rc = HYPERVISOR_vcpu_op(VCPUOP_send_nmi, PCPU_GET(vcpu_id), NULL);
break;
case APIC_IPI_DEST_ALL:
CPU_FOREACH(cpu) {
rc = HYPERVISOR_vcpu_op(VCPUOP_send_nmi,
PCPU_ID_GET(cpu, vcpu_id), NULL);
if (rc != 0)
break;
}
break;
case APIC_IPI_DEST_OTHERS:
CPU_FOREACH(cpu) {
if (cpu != PCPU_GET(cpuid)) {
rc = HYPERVISOR_vcpu_op(VCPUOP_send_nmi,
PCPU_ID_GET(cpu, vcpu_id), NULL);
if (rc != 0)
break;
}
}
break;
default:
rc = HYPERVISOR_vcpu_op(VCPUOP_send_nmi,
PCPU_ID_GET(apic_cpuid(dest), vcpu_id), NULL);
break;
}
return rc;
}
#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;
static bool pvnmi = true;
if (vector >= IPI_NMI_FIRST) {
if (pvnmi) {
int rc = send_nmi(dest);
if (rc != 0) {
printf(
"Sending NMI using hypercall failed (%d) switching to APIC\n", rc);
pvnmi = false;
native_ipi_vectored(vector, dest);
}
} else
native_ipi_vectored(vector, dest);
return;
}
ipi_idx = IPI_TO_IDX(vector);
if (ipi_idx >= nitems(xen_ipis))
panic("IPI out of range");
switch(dest) {
case APIC_IPI_DEST_SELF:
ipi_handle = DPCPU_GET(ipi_handle);
xen_intr_signal(ipi_handle[ipi_idx]);
break;
case APIC_IPI_DEST_ALL:
CPU_FOREACH(to_cpu) {
ipi_handle = DPCPU_ID_GET(to_cpu, ipi_handle);
xen_intr_signal(ipi_handle[ipi_idx]);
}
break;
case APIC_IPI_DEST_OTHERS:
self = PCPU_GET(cpuid);
CPU_FOREACH(to_cpu) {
if (to_cpu != self) {
ipi_handle = DPCPU_ID_GET(to_cpu, ipi_handle);
xen_intr_signal(ipi_handle[ipi_idx]);
}
}
break;
default:
to_cpu = apic_cpuid(dest);
ipi_handle = DPCPU_ID_GET(to_cpu, ipi_handle);
xen_intr_signal(ipi_handle[ipi_idx]);
break;
}
}
/*---------------------------- XEN PV IPI Handlers ---------------------------*/
/*
* These are C clones of the ASM functions found in apic_vector.
*/
static int
xen_ipi_bitmap_handler(void *arg)
{
struct trapframe *frame;
frame = arg;
ipi_bitmap_handler(*frame);
return (FILTER_HANDLED);
}
static int
xen_smp_rendezvous_action(void *arg)
{
#ifdef COUNT_IPIS
(*ipi_rendezvous_counts[PCPU_GET(cpuid)])++;
#endif /* COUNT_IPIS */
smp_rendezvous_action();
return (FILTER_HANDLED);
}
#ifdef __amd64__
static int
xen_invlop(void *arg)
{
invlop_handler();
return (FILTER_HANDLED);
}
#else /* __i386__ */
static int
xen_invltlb(void *arg)
{
invltlb_handler();
return (FILTER_HANDLED);
}
static int
xen_invlpg(void *arg)
{
invlpg_handler();
return (FILTER_HANDLED);
}
static int
xen_invlrng(void *arg)
{
invlrng_handler();
return (FILTER_HANDLED);
}
static int
xen_invlcache(void *arg)
{
invlcache_handler();
return (FILTER_HANDLED);
}
#endif /* __amd64__ */
static int
xen_cpustop_handler(void *arg)
{
cpustop_handler();
return (FILTER_HANDLED);
}
static int
xen_cpususpend_handler(void *arg)
{
cpususpend_handler();
return (FILTER_HANDLED);
}
static int
xen_ipi_swi_handler(void *arg)
{
struct trapframe *frame = arg;
ipi_swi_handler(*frame);
return (FILTER_HANDLED);
}
/*----------------------------- XEN PV IPI setup -----------------------------*/
/*
* Those functions are provided outside of the Xen PV APIC implementation
* so PVHVM guests can also use PV IPIs without having an actual Xen PV APIC,
* because on PVHVM there's an emulated LAPIC provided by Xen.
*/
static void
xen_cpu_ipi_init(int cpu)
{
xen_intr_handle_t *ipi_handle;
const struct xen_ipi_handler *ipi;
int idx, rc;
ipi_handle = DPCPU_ID_GET(cpu, ipi_handle);
for (ipi = xen_ipis, idx = 0; idx < nitems(xen_ipis); ipi++, idx++) {
if (ipi->filter == NULL) {
ipi_handle[idx] = NULL;
continue;
}
rc = xen_intr_alloc_and_bind_ipi(cpu, ipi->filter,
INTR_TYPE_TTY, &ipi_handle[idx]);
if (rc != 0)
panic("Unable to allocate a XEN IPI port");
xen_intr_describe(ipi_handle[idx], "%s", ipi->description);
}
}
static void
xen_setup_cpus(void)
{
uint32_t regs[4];
int i;
if (!xen_vector_callback_enabled)
return;
/*
* Check whether the APIC virtualization is hardware assisted, as
* that's faster than using event channels because it avoids the VM
* exit.
*/
KASSERT(xen_cpuid_base != 0, ("Invalid base Xen CPUID leaf"));
cpuid_count(xen_cpuid_base + 4, 0, regs);
if ((x2apic_mode && (regs[0] & XEN_HVM_CPUID_X2APIC_VIRT)) ||
(!x2apic_mode && (regs[0] & XEN_HVM_CPUID_APIC_ACCESS_VIRT)))
return;
CPU_FOREACH(i)
xen_cpu_ipi_init(i);
/* Set the xen pv ipi ops to replace the native ones */
ipi_vectored = xen_pv_lapic_ipi_vectored;
native_ipi_vectored = ipi_vectored;
}
/* Switch to using PV IPIs as soon as the vcpu_id is set. */
SYSINIT(xen_setup_cpus, SI_SUB_SMP, SI_ORDER_SECOND, xen_setup_cpus, NULL);
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