freebsd-dev/sys/x86/xen/xen_apic.c
Konstantin Belousov a546448b8d Rewrite amd64 PCID implementation to follow an algorithm described in
the Vahalia' "Unix Internals" section 15.12 "Other TLB Consistency
Algorithms".  The same algorithm is already utilized by the MIPS pmap
to handle ASIDs.

The PCID for the address space is now allocated per-cpu during context
switch to the thread using pmap, when no PCID on the cpu was ever
allocated, or the current PCID is invalidated.  If the PCID is reused,
bit 63 of %cr3 can be set to avoid TLB flush.

Each cpu has PCID' algorithm generation count, which is saved in the
pmap pcpu block when pcpu PCID is allocated.  On invalidation, the
pmap generation count is zeroed, which signals the context switch code
that already allocated PCID is no longer valid.  The implication is
the TLB shootdown for the given cpu/address space, due to the
allocation of new PCID.

The pm_save mask is no longer has to be tracked, which (significantly)
reduces the targets of the TLB shootdown IPIs.  Previously, pm_save
was reset only on pmap_invalidate_all(), which made it accumulate the
cpuids of all processors on which the thread was scheduled between
full TLB shootdowns.

Besides reducing the amount of TLB shootdowns and removing atomics to
update pm_saves in the context switch code, the algorithm is much
simpler than the maintanence of pm_save and selection of the right
address space in the shootdown IPI handler.

Reviewed by:	alc
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	3 weeks
2015-05-09 19:11:01 +00:00

548 lines
11 KiB
C

/*
* 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>
__FBSDID("$FreeBSD$");
#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/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 <xen/interface/vcpu.h>
/*--------------------------------- Macros -----------------------------------*/
#define XEN_APIC_UNSUPPORTED \
panic("%s: not available in Xen PV port.", __func__)
/*--------------------------- Forward Declarations ---------------------------*/
#ifdef SMP
static driver_filter_t xen_smp_rendezvous_action;
static driver_filter_t xen_invltlb;
static driver_filter_t xen_invlpg;
static driver_filter_t xen_invlrng;
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
/*---------------------------- Extern Declarations ---------------------------*/
/* Variables used by mp_machdep to perform the MMU related IPIs */
#ifdef __amd64__
extern int pmap_pcid_enabled;
#endif
/*---------------------------------- Macros ----------------------------------*/
#define IPI_TO_IDX(ipi) ((ipi) - APIC_IPI_INTS)
/*--------------------------------- Xen IPIs ---------------------------------*/
#ifdef SMP
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" },
[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" },
[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
/*------------------------------- Per-CPU Data -------------------------------*/
#ifdef SMP
DPCPU_DEFINE(xen_intr_handle_t, ipi_handle[nitems(xen_ipis)]);
#endif
/*------------------------------- Xen PV APIC --------------------------------*/
static void
xen_pv_lapic_create(u_int apic_id, int boot_cpu)
{
#ifdef SMP
cpu_add(apic_id, boot_cpu);
#endif
}
static void
xen_pv_lapic_init(vm_paddr_t addr)
{
}
static void
xen_pv_lapic_setup(int boot)
{
}
static void
xen_pv_lapic_dump(const char *str)
{
printf("cpu%d %s XEN PV LAPIC\n", PCPU_GET(cpuid), str);
}
static void
xen_pv_lapic_disable(void)
{
}
static void
xen_pv_lapic_eoi(void)
{
XEN_APIC_UNSUPPORTED;
}
static int
xen_pv_lapic_id(void)
{
return (PCPU_GET(apic_id));
}
static int
xen_pv_lapic_intr_pending(u_int vector)
{
XEN_APIC_UNSUPPORTED;
return (0);
}
static u_int
xen_pv_apic_cpuid(u_int apic_id)
{
#ifdef SMP
return (apic_cpuids[apic_id]);
#else
return (0);
#endif
}
static u_int
xen_pv_apic_alloc_vector(u_int apic_id, u_int irq)
{
XEN_APIC_UNSUPPORTED;
return (0);
}
static u_int
xen_pv_apic_alloc_vectors(u_int apic_id, u_int *irqs, u_int count, u_int align)
{
XEN_APIC_UNSUPPORTED;
return (0);
}
static void
xen_pv_apic_disable_vector(u_int apic_id, u_int vector)
{
XEN_APIC_UNSUPPORTED;
}
static void
xen_pv_apic_enable_vector(u_int apic_id, u_int vector)
{
XEN_APIC_UNSUPPORTED;
}
static void
xen_pv_apic_free_vector(u_int apic_id, u_int vector, u_int irq)
{
XEN_APIC_UNSUPPORTED;
}
static void
xen_pv_lapic_set_logical_id(u_int apic_id, u_int cluster, u_int cluster_id)
{
XEN_APIC_UNSUPPORTED;
}
static int
xen_pv_lapic_enable_pmc(void)
{
XEN_APIC_UNSUPPORTED;
return (0);
}
static void
xen_pv_lapic_disable_pmc(void)
{
XEN_APIC_UNSUPPORTED;
}
static void
xen_pv_lapic_reenable_pmc(void)
{
XEN_APIC_UNSUPPORTED;
}
static void
xen_pv_lapic_enable_cmc(void)
{
}
#ifdef SMP
static void
xen_pv_lapic_ipi_raw(register_t icrlo, u_int dest)
{
XEN_APIC_UNSUPPORTED;
}
static void
xen_pv_lapic_ipi_vectored(u_int vector, int dest)
{
xen_intr_handle_t *ipi_handle;
int ipi_idx, to_cpu, self;
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;
}
}
static int
xen_pv_lapic_ipi_wait(int delay)
{
XEN_APIC_UNSUPPORTED;
return (0);
}
static int
xen_pv_lapic_ipi_alloc(inthand_t *ipifunc)
{
XEN_APIC_UNSUPPORTED;
return (-1);
}
static void
xen_pv_lapic_ipi_free(int vector)
{
XEN_APIC_UNSUPPORTED;
}
#endif /* SMP */
static int
xen_pv_lapic_set_lvt_mask(u_int apic_id, u_int lvt, u_char masked)
{
XEN_APIC_UNSUPPORTED;
return (0);
}
static int
xen_pv_lapic_set_lvt_mode(u_int apic_id, u_int lvt, uint32_t mode)
{
XEN_APIC_UNSUPPORTED;
return (0);
}
static int
xen_pv_lapic_set_lvt_polarity(u_int apic_id, u_int lvt, enum intr_polarity pol)
{
XEN_APIC_UNSUPPORTED;
return (0);
}
static int
xen_pv_lapic_set_lvt_triggermode(u_int apic_id, u_int lvt,
enum intr_trigger trigger)
{
XEN_APIC_UNSUPPORTED;
return (0);
}
/* Xen apic_ops implementation */
struct apic_ops xen_apic_ops = {
.create = xen_pv_lapic_create,
.init = xen_pv_lapic_init,
.xapic_mode = xen_pv_lapic_disable,
.setup = xen_pv_lapic_setup,
.dump = xen_pv_lapic_dump,
.disable = xen_pv_lapic_disable,
.eoi = xen_pv_lapic_eoi,
.id = xen_pv_lapic_id,
.intr_pending = xen_pv_lapic_intr_pending,
.set_logical_id = xen_pv_lapic_set_logical_id,
.cpuid = xen_pv_apic_cpuid,
.alloc_vector = xen_pv_apic_alloc_vector,
.alloc_vectors = xen_pv_apic_alloc_vectors,
.enable_vector = xen_pv_apic_enable_vector,
.disable_vector = xen_pv_apic_disable_vector,
.free_vector = xen_pv_apic_free_vector,
.enable_pmc = xen_pv_lapic_enable_pmc,
.disable_pmc = xen_pv_lapic_disable_pmc,
.reenable_pmc = xen_pv_lapic_reenable_pmc,
.enable_cmc = xen_pv_lapic_enable_cmc,
#ifdef SMP
.ipi_raw = xen_pv_lapic_ipi_raw,
.ipi_vectored = xen_pv_lapic_ipi_vectored,
.ipi_wait = xen_pv_lapic_ipi_wait,
.ipi_alloc = xen_pv_lapic_ipi_alloc,
.ipi_free = xen_pv_lapic_ipi_free,
#endif
.set_lvt_mask = xen_pv_lapic_set_lvt_mask,
.set_lvt_mode = xen_pv_lapic_set_lvt_mode,
.set_lvt_polarity = xen_pv_lapic_set_lvt_polarity,
.set_lvt_triggermode = xen_pv_lapic_set_lvt_triggermode,
};
#ifdef SMP
/*---------------------------- 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);
}
static int
xen_invltlb(void *arg)
{
invltlb_handler();
return (FILTER_HANDLED);
}
#ifdef __amd64__
static int
xen_invltlb_invpcid(void *arg)
{
invltlb_invpcid_handler();
return (FILTER_HANDLED);
}
static int
xen_invltlb_pcid(void *arg)
{
invltlb_pcid_handler();
return (FILTER_HANDLED);
}
#endif
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);
}
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_cpustophard_handler(void *arg)
{
ipi_nmi_handler();
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;
device_t dev;
int idx, rc;
ipi_handle = DPCPU_ID_GET(cpu, ipi_handle);
dev = pcpu_find(cpu)->pc_device;
KASSERT((dev != NULL), ("NULL pcpu device_t"));
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(dev, 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)
{
int i;
if (!xen_vector_callback_enabled)
return;
#ifdef __amd64__
if (pmap_pcid_enabled) {
xen_ipis[IPI_TO_IDX(IPI_INVLTLB)].filter = invpcid_works ?
xen_invltlb_invpcid : xen_invltlb_pcid;
}
#endif
CPU_FOREACH(i)
xen_cpu_ipi_init(i);
/* Set the xen pv ipi ops to replace the native ones */
if (xen_hvm_domain())
apic_ops.ipi_vectored = xen_pv_lapic_ipi_vectored;
}
/* We need to setup IPIs before APs are started */
SYSINIT(xen_setup_cpus, SI_SUB_SMP-1, SI_ORDER_FIRST, xen_setup_cpus, NULL);
#endif /* SMP */