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linux-next/include/linux/dmar.h

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Intel IOMMU: DMAR detection and parsing logic This patch supports the upcomming Intel IOMMU hardware a.k.a. Intel(R) Virtualization Technology for Directed I/O Architecture and the hardware spec for the same can be found here http://www.intel.com/technology/virtualization/index.htm FAQ! (questions from akpm, answers from ak) > So... what's all this code for? > > I assume that the intent here is to speed things up under Xen, etc? Yes in some cases, but not this code. That would be the Xen version of this code that could potentially assign whole devices to guests. I expect this to be only useful in some special cases though because most hardware is not virtualizable and you typically want an own instance for each guest. Ok at some point KVM might implement this too; i likely would use this code for this. > Do we > have any benchmark results to help us to decide whether a merge would be > justified? The main advantage for doing it in the normal kernel is not performance, but more safety. Broken devices won't be able to corrupt memory by doing random DMA. Unfortunately that doesn't work for graphics yet, for that need user space interfaces for the X server are needed. There are some potential performance benefits too: - When you have a device that cannot address the complete address range an IOMMU can remap its memory instead of bounce buffering. Remapping is likely cheaper than copying. - The IOMMU can merge sg lists into a single virtual block. This could potentially speed up SG IO when the device is slow walking SG lists. [I long ago benchmarked 5% on some block benchmark with an old MPT Fusion; but it probably depends a lot on the HBA] And you get better driver debugging because unexpected memory accesses from the devices will cause a trappable event. > > Does it slow anything down? It adds more overhead to each IO so yes. This patch: Add support for early detection and parsing of DMAR's (DMA Remapping) reported to OS via ACPI tables. DMA remapping(DMAR) devices support enables independent address translations for Direct Memory Access(DMA) from Devices. These DMA remapping devices are reported via ACPI tables and includes pci device scope covered by these DMA remapping device. For detailed info on the specification of "Intel(R) Virtualization Technology for Directed I/O Architecture" please see http://www.intel.com/technology/virtualization/index.htm Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Andi Kleen <ak@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Muli Ben-Yehuda <muli@il.ibm.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Ashok Raj <ashok.raj@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Christoph Lameter <clameter@sgi.com> Cc: Greg KH <greg@kroah.com> Cc: Len Brown <lenb@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-22 07:41:41 +08:00
/*
* Copyright (c) 2006, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place - Suite 330, Boston, MA 02111-1307 USA.
*
* Copyright (C) Ashok Raj <ashok.raj@intel.com>
* Copyright (C) Shaohua Li <shaohua.li@intel.com>
*/
#ifndef __DMAR_H__
#define __DMAR_H__
#include <linux/acpi.h>
#include <linux/types.h>
#include <linux/msi.h>
#include <linux/irqreturn.h>
2014-02-19 14:07:33 +08:00
#include <linux/rwsem.h>
#include <linux/rcupdate.h>
Intel IOMMU: DMAR detection and parsing logic This patch supports the upcomming Intel IOMMU hardware a.k.a. Intel(R) Virtualization Technology for Directed I/O Architecture and the hardware spec for the same can be found here http://www.intel.com/technology/virtualization/index.htm FAQ! (questions from akpm, answers from ak) > So... what's all this code for? > > I assume that the intent here is to speed things up under Xen, etc? Yes in some cases, but not this code. That would be the Xen version of this code that could potentially assign whole devices to guests. I expect this to be only useful in some special cases though because most hardware is not virtualizable and you typically want an own instance for each guest. Ok at some point KVM might implement this too; i likely would use this code for this. > Do we > have any benchmark results to help us to decide whether a merge would be > justified? The main advantage for doing it in the normal kernel is not performance, but more safety. Broken devices won't be able to corrupt memory by doing random DMA. Unfortunately that doesn't work for graphics yet, for that need user space interfaces for the X server are needed. There are some potential performance benefits too: - When you have a device that cannot address the complete address range an IOMMU can remap its memory instead of bounce buffering. Remapping is likely cheaper than copying. - The IOMMU can merge sg lists into a single virtual block. This could potentially speed up SG IO when the device is slow walking SG lists. [I long ago benchmarked 5% on some block benchmark with an old MPT Fusion; but it probably depends a lot on the HBA] And you get better driver debugging because unexpected memory accesses from the devices will cause a trappable event. > > Does it slow anything down? It adds more overhead to each IO so yes. This patch: Add support for early detection and parsing of DMAR's (DMA Remapping) reported to OS via ACPI tables. DMA remapping(DMAR) devices support enables independent address translations for Direct Memory Access(DMA) from Devices. These DMA remapping devices are reported via ACPI tables and includes pci device scope covered by these DMA remapping device. For detailed info on the specification of "Intel(R) Virtualization Technology for Directed I/O Architecture" please see http://www.intel.com/technology/virtualization/index.htm Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Andi Kleen <ak@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Muli Ben-Yehuda <muli@il.ibm.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Ashok Raj <ashok.raj@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Christoph Lameter <clameter@sgi.com> Cc: Greg KH <greg@kroah.com> Cc: Len Brown <lenb@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-22 07:41:41 +08:00
struct acpi_dmar_header;
x86, x2apic: Enable the bios request for x2apic optout On the platforms which are x2apic and interrupt-remapping capable, Linux kernel is enabling x2apic even if the BIOS doesn't. This is to take advantage of the features that x2apic brings in. Some of the OEM platforms are running into issues because of this, as their bios is not x2apic aware. For example, this was resulting in interrupt migration issues on one of the platforms. Also if the BIOS SMI handling uses APIC interface to send SMI's, then the BIOS need to be aware of x2apic mode that OS has enabled. On some of these platforms, BIOS doesn't have a HW mechanism to turnoff the x2apic feature to prevent OS from enabling it. To resolve this mess, recent changes to the VT-d2 specification: http://download.intel.com/technology/computing/vptech/Intel(r)_VT_for_Direct_IO.pdf includes a mechanism that provides BIOS a way to request system software to opt out of enabling x2apic mode. Look at the x2apic optout flag in the DMAR tables before enabling the x2apic mode in the platform. Also print a warning that we have disabled x2apic based on the BIOS request. Kernel boot parameter "intremap=no_x2apic_optout" can be used to override the BIOS x2apic optout request. Signed-off-by: Youquan Song <youquan.song@intel.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: yinghai@kernel.org Cc: joerg.roedel@amd.com Cc: tony.luck@intel.com Cc: dwmw2@infradead.org Link: http://lkml.kernel.org/r/20110824001456.171766616@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-08-24 08:05:18 +08:00
/* DMAR Flags */
#define DMAR_INTR_REMAP 0x1
#define DMAR_X2APIC_OPT_OUT 0x2
struct intel_iommu;
struct dmar_dev_scope {
struct device __rcu *dev;
u8 bus;
u8 devfn;
};
#ifdef CONFIG_DMAR_TABLE
x86, x2apic: Enable the bios request for x2apic optout On the platforms which are x2apic and interrupt-remapping capable, Linux kernel is enabling x2apic even if the BIOS doesn't. This is to take advantage of the features that x2apic brings in. Some of the OEM platforms are running into issues because of this, as their bios is not x2apic aware. For example, this was resulting in interrupt migration issues on one of the platforms. Also if the BIOS SMI handling uses APIC interface to send SMI's, then the BIOS need to be aware of x2apic mode that OS has enabled. On some of these platforms, BIOS doesn't have a HW mechanism to turnoff the x2apic feature to prevent OS from enabling it. To resolve this mess, recent changes to the VT-d2 specification: http://download.intel.com/technology/computing/vptech/Intel(r)_VT_for_Direct_IO.pdf includes a mechanism that provides BIOS a way to request system software to opt out of enabling x2apic mode. Look at the x2apic optout flag in the DMAR tables before enabling the x2apic mode in the platform. Also print a warning that we have disabled x2apic based on the BIOS request. Kernel boot parameter "intremap=no_x2apic_optout" can be used to override the BIOS x2apic optout request. Signed-off-by: Youquan Song <youquan.song@intel.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: yinghai@kernel.org Cc: joerg.roedel@amd.com Cc: tony.luck@intel.com Cc: dwmw2@infradead.org Link: http://lkml.kernel.org/r/20110824001456.171766616@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-08-24 08:05:18 +08:00
extern struct acpi_table_header *dmar_tbl;
struct dmar_drhd_unit {
struct list_head list; /* list of drhd units */
struct acpi_dmar_header *hdr; /* ACPI header */
u64 reg_base_addr; /* register base address*/
struct dmar_dev_scope *devices;/* target device array */
int devices_cnt; /* target device count */
u16 segment; /* PCI domain */
u8 ignored:1; /* ignore drhd */
u8 include_all:1;
struct intel_iommu *iommu;
};
struct dmar_pci_path {
u8 bus;
u8 device;
u8 function;
};
iommu/vt-d: Update DRHD/RMRR/ATSR device scope caches when PCI hotplug happens Current Intel DMAR/IOMMU driver assumes that all PCI devices associated with DMAR/RMRR/ATSR device scope arrays are created at boot time and won't change at runtime, so it caches pointers of associated PCI device object. That assumption may be wrong now due to: 1) introduction of PCI host bridge hotplug 2) PCI device hotplug through sysfs interfaces. Wang Yijing has tried to solve this issue by caching <bus, dev, func> tupple instead of the PCI device object pointer, but that's still unreliable because PCI bus number may change in case of hotplug. Please refer to http://lkml.org/lkml/2013/11/5/64 Message from Yingjing's mail: after remove and rescan a pci device [ 611.857095] dmar: DRHD: handling fault status reg 2 [ 611.857109] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff7000 [ 611.857109] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.857524] dmar: DRHD: handling fault status reg 102 [ 611.857534] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff6000 [ 611.857534] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.857936] dmar: DRHD: handling fault status reg 202 [ 611.857947] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff5000 [ 611.857947] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.858351] dmar: DRHD: handling fault status reg 302 [ 611.858362] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff4000 [ 611.858362] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.860819] IPv6: ADDRCONF(NETDEV_UP): eth3: link is not ready [ 611.860983] dmar: DRHD: handling fault status reg 402 [ 611.860995] dmar: INTR-REMAP: Request device [[86:00.3] fault index a4 [ 611.860995] INTR-REMAP:[fault reason 34] Present field in the IRTE entry is clear This patch introduces a new mechanism to update the DRHD/RMRR/ATSR device scope caches by hooking PCI bus notification. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Signed-off-by: Joerg Roedel <joro@8bytes.org>
2014-02-19 14:07:35 +08:00
struct dmar_pci_notify_info {
struct pci_dev *dev;
unsigned long event;
int bus;
u16 seg;
u16 level;
struct dmar_pci_path path[];
iommu/vt-d: Update DRHD/RMRR/ATSR device scope caches when PCI hotplug happens Current Intel DMAR/IOMMU driver assumes that all PCI devices associated with DMAR/RMRR/ATSR device scope arrays are created at boot time and won't change at runtime, so it caches pointers of associated PCI device object. That assumption may be wrong now due to: 1) introduction of PCI host bridge hotplug 2) PCI device hotplug through sysfs interfaces. Wang Yijing has tried to solve this issue by caching <bus, dev, func> tupple instead of the PCI device object pointer, but that's still unreliable because PCI bus number may change in case of hotplug. Please refer to http://lkml.org/lkml/2013/11/5/64 Message from Yingjing's mail: after remove and rescan a pci device [ 611.857095] dmar: DRHD: handling fault status reg 2 [ 611.857109] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff7000 [ 611.857109] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.857524] dmar: DRHD: handling fault status reg 102 [ 611.857534] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff6000 [ 611.857534] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.857936] dmar: DRHD: handling fault status reg 202 [ 611.857947] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff5000 [ 611.857947] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.858351] dmar: DRHD: handling fault status reg 302 [ 611.858362] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff4000 [ 611.858362] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.860819] IPv6: ADDRCONF(NETDEV_UP): eth3: link is not ready [ 611.860983] dmar: DRHD: handling fault status reg 402 [ 611.860995] dmar: INTR-REMAP: Request device [[86:00.3] fault index a4 [ 611.860995] INTR-REMAP:[fault reason 34] Present field in the IRTE entry is clear This patch introduces a new mechanism to update the DRHD/RMRR/ATSR device scope caches by hooking PCI bus notification. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Signed-off-by: Joerg Roedel <joro@8bytes.org>
2014-02-19 14:07:35 +08:00
} __attribute__((packed));
2014-02-19 14:07:33 +08:00
extern struct rw_semaphore dmar_global_lock;
extern struct list_head dmar_drhd_units;
#define for_each_drhd_unit(drhd) \
list_for_each_entry_rcu(drhd, &dmar_drhd_units, list)
#define for_each_active_drhd_unit(drhd) \
list_for_each_entry_rcu(drhd, &dmar_drhd_units, list) \
if (drhd->ignored) {} else
#define for_each_active_iommu(i, drhd) \
list_for_each_entry_rcu(drhd, &dmar_drhd_units, list) \
if (i=drhd->iommu, drhd->ignored) {} else
#define for_each_iommu(i, drhd) \
list_for_each_entry_rcu(drhd, &dmar_drhd_units, list) \
if (i=drhd->iommu, 0) {} else
static inline bool dmar_rcu_check(void)
{
return rwsem_is_locked(&dmar_global_lock) ||
system_state == SYSTEM_BOOTING;
}
#define dmar_rcu_dereference(p) rcu_dereference_check((p), dmar_rcu_check())
#define for_each_dev_scope(a, c, p, d) \
for ((p) = 0; ((d) = (p) < (c) ? dmar_rcu_dereference((a)[(p)].dev) : \
NULL, (p) < (c)); (p)++)
#define for_each_active_dev_scope(a, c, p, d) \
for_each_dev_scope((a), (c), (p), (d)) if (!(d)) { continue; } else
extern int dmar_table_init(void);
extern int dmar_dev_scope_init(void);
extern int dmar_parse_dev_scope(void *start, void *end, int *cnt,
struct dmar_dev_scope **devices, u16 segment);
extern void *dmar_alloc_dev_scope(void *start, void *end, int *cnt);
extern void dmar_free_dev_scope(struct dmar_dev_scope **devices, int *cnt);
iommu/vt-d: Update DRHD/RMRR/ATSR device scope caches when PCI hotplug happens Current Intel DMAR/IOMMU driver assumes that all PCI devices associated with DMAR/RMRR/ATSR device scope arrays are created at boot time and won't change at runtime, so it caches pointers of associated PCI device object. That assumption may be wrong now due to: 1) introduction of PCI host bridge hotplug 2) PCI device hotplug through sysfs interfaces. Wang Yijing has tried to solve this issue by caching <bus, dev, func> tupple instead of the PCI device object pointer, but that's still unreliable because PCI bus number may change in case of hotplug. Please refer to http://lkml.org/lkml/2013/11/5/64 Message from Yingjing's mail: after remove and rescan a pci device [ 611.857095] dmar: DRHD: handling fault status reg 2 [ 611.857109] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff7000 [ 611.857109] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.857524] dmar: DRHD: handling fault status reg 102 [ 611.857534] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff6000 [ 611.857534] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.857936] dmar: DRHD: handling fault status reg 202 [ 611.857947] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff5000 [ 611.857947] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.858351] dmar: DRHD: handling fault status reg 302 [ 611.858362] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff4000 [ 611.858362] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.860819] IPv6: ADDRCONF(NETDEV_UP): eth3: link is not ready [ 611.860983] dmar: DRHD: handling fault status reg 402 [ 611.860995] dmar: INTR-REMAP: Request device [[86:00.3] fault index a4 [ 611.860995] INTR-REMAP:[fault reason 34] Present field in the IRTE entry is clear This patch introduces a new mechanism to update the DRHD/RMRR/ATSR device scope caches by hooking PCI bus notification. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Signed-off-by: Joerg Roedel <joro@8bytes.org>
2014-02-19 14:07:35 +08:00
extern int dmar_insert_dev_scope(struct dmar_pci_notify_info *info,
void *start, void*end, u16 segment,
struct dmar_dev_scope *devices,
iommu/vt-d: Update DRHD/RMRR/ATSR device scope caches when PCI hotplug happens Current Intel DMAR/IOMMU driver assumes that all PCI devices associated with DMAR/RMRR/ATSR device scope arrays are created at boot time and won't change at runtime, so it caches pointers of associated PCI device object. That assumption may be wrong now due to: 1) introduction of PCI host bridge hotplug 2) PCI device hotplug through sysfs interfaces. Wang Yijing has tried to solve this issue by caching <bus, dev, func> tupple instead of the PCI device object pointer, but that's still unreliable because PCI bus number may change in case of hotplug. Please refer to http://lkml.org/lkml/2013/11/5/64 Message from Yingjing's mail: after remove and rescan a pci device [ 611.857095] dmar: DRHD: handling fault status reg 2 [ 611.857109] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff7000 [ 611.857109] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.857524] dmar: DRHD: handling fault status reg 102 [ 611.857534] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff6000 [ 611.857534] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.857936] dmar: DRHD: handling fault status reg 202 [ 611.857947] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff5000 [ 611.857947] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.858351] dmar: DRHD: handling fault status reg 302 [ 611.858362] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff4000 [ 611.858362] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.860819] IPv6: ADDRCONF(NETDEV_UP): eth3: link is not ready [ 611.860983] dmar: DRHD: handling fault status reg 402 [ 611.860995] dmar: INTR-REMAP: Request device [[86:00.3] fault index a4 [ 611.860995] INTR-REMAP:[fault reason 34] Present field in the IRTE entry is clear This patch introduces a new mechanism to update the DRHD/RMRR/ATSR device scope caches by hooking PCI bus notification. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Signed-off-by: Joerg Roedel <joro@8bytes.org>
2014-02-19 14:07:35 +08:00
int devices_cnt);
extern int dmar_remove_dev_scope(struct dmar_pci_notify_info *info,
u16 segment, struct dmar_dev_scope *devices,
iommu/vt-d: Update DRHD/RMRR/ATSR device scope caches when PCI hotplug happens Current Intel DMAR/IOMMU driver assumes that all PCI devices associated with DMAR/RMRR/ATSR device scope arrays are created at boot time and won't change at runtime, so it caches pointers of associated PCI device object. That assumption may be wrong now due to: 1) introduction of PCI host bridge hotplug 2) PCI device hotplug through sysfs interfaces. Wang Yijing has tried to solve this issue by caching <bus, dev, func> tupple instead of the PCI device object pointer, but that's still unreliable because PCI bus number may change in case of hotplug. Please refer to http://lkml.org/lkml/2013/11/5/64 Message from Yingjing's mail: after remove and rescan a pci device [ 611.857095] dmar: DRHD: handling fault status reg 2 [ 611.857109] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff7000 [ 611.857109] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.857524] dmar: DRHD: handling fault status reg 102 [ 611.857534] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff6000 [ 611.857534] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.857936] dmar: DRHD: handling fault status reg 202 [ 611.857947] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff5000 [ 611.857947] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.858351] dmar: DRHD: handling fault status reg 302 [ 611.858362] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff4000 [ 611.858362] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.860819] IPv6: ADDRCONF(NETDEV_UP): eth3: link is not ready [ 611.860983] dmar: DRHD: handling fault status reg 402 [ 611.860995] dmar: INTR-REMAP: Request device [[86:00.3] fault index a4 [ 611.860995] INTR-REMAP:[fault reason 34] Present field in the IRTE entry is clear This patch introduces a new mechanism to update the DRHD/RMRR/ATSR device scope caches by hooking PCI bus notification. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Signed-off-by: Joerg Roedel <joro@8bytes.org>
2014-02-19 14:07:35 +08:00
int count);
/* Intel IOMMU detection */
extern int detect_intel_iommu(void);
extern int enable_drhd_fault_handling(void);
#ifdef CONFIG_INTEL_IOMMU
extern int iommu_detected, no_iommu;
extern int intel_iommu_init(void);
extern int dmar_parse_one_rmrr(struct acpi_dmar_header *header);
extern int dmar_parse_one_atsr(struct acpi_dmar_header *header);
extern int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info);
#else /* !CONFIG_INTEL_IOMMU: */
static inline int intel_iommu_init(void) { return -ENODEV; }
static inline int dmar_parse_one_rmrr(struct acpi_dmar_header *header)
{
return 0;
}
static inline int dmar_parse_one_atsr(struct acpi_dmar_header *header)
{
return 0;
}
static inline int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info)
{
return 0;
}
#endif /* CONFIG_INTEL_IOMMU */
#endif /* CONFIG_DMAR_TABLE */
struct irte {
union {
struct {
__u64 present : 1,
fpd : 1,
dst_mode : 1,
redir_hint : 1,
trigger_mode : 1,
dlvry_mode : 3,
avail : 4,
__reserved_1 : 4,
vector : 8,
__reserved_2 : 8,
dest_id : 32;
};
__u64 low;
};
union {
struct {
__u64 sid : 16,
sq : 2,
svt : 2,
__reserved_3 : 44;
};
__u64 high;
};
};
x86, x2apic: Enable the bios request for x2apic optout On the platforms which are x2apic and interrupt-remapping capable, Linux kernel is enabling x2apic even if the BIOS doesn't. This is to take advantage of the features that x2apic brings in. Some of the OEM platforms are running into issues because of this, as their bios is not x2apic aware. For example, this was resulting in interrupt migration issues on one of the platforms. Also if the BIOS SMI handling uses APIC interface to send SMI's, then the BIOS need to be aware of x2apic mode that OS has enabled. On some of these platforms, BIOS doesn't have a HW mechanism to turnoff the x2apic feature to prevent OS from enabling it. To resolve this mess, recent changes to the VT-d2 specification: http://download.intel.com/technology/computing/vptech/Intel(r)_VT_for_Direct_IO.pdf includes a mechanism that provides BIOS a way to request system software to opt out of enabling x2apic mode. Look at the x2apic optout flag in the DMAR tables before enabling the x2apic mode in the platform. Also print a warning that we have disabled x2apic based on the BIOS request. Kernel boot parameter "intremap=no_x2apic_optout" can be used to override the BIOS x2apic optout request. Signed-off-by: Youquan Song <youquan.song@intel.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: yinghai@kernel.org Cc: joerg.roedel@amd.com Cc: tony.luck@intel.com Cc: dwmw2@infradead.org Link: http://lkml.kernel.org/r/20110824001456.171766616@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-08-24 08:05:18 +08:00
enum {
IRQ_REMAP_XAPIC_MODE,
IRQ_REMAP_X2APIC_MODE,
};
/* Can't use the common MSI interrupt functions
* since DMAR is not a pci device
*/
struct irq_data;
extern void dmar_msi_unmask(struct irq_data *data);
extern void dmar_msi_mask(struct irq_data *data);
extern void dmar_msi_read(int irq, struct msi_msg *msg);
extern void dmar_msi_write(int irq, struct msi_msg *msg);
extern int dmar_set_interrupt(struct intel_iommu *iommu);
extern irqreturn_t dmar_fault(int irq, void *dev_id);
extern int arch_setup_dmar_msi(unsigned int irq);
Intel IOMMU: DMAR detection and parsing logic This patch supports the upcomming Intel IOMMU hardware a.k.a. Intel(R) Virtualization Technology for Directed I/O Architecture and the hardware spec for the same can be found here http://www.intel.com/technology/virtualization/index.htm FAQ! (questions from akpm, answers from ak) > So... what's all this code for? > > I assume that the intent here is to speed things up under Xen, etc? Yes in some cases, but not this code. That would be the Xen version of this code that could potentially assign whole devices to guests. I expect this to be only useful in some special cases though because most hardware is not virtualizable and you typically want an own instance for each guest. Ok at some point KVM might implement this too; i likely would use this code for this. > Do we > have any benchmark results to help us to decide whether a merge would be > justified? The main advantage for doing it in the normal kernel is not performance, but more safety. Broken devices won't be able to corrupt memory by doing random DMA. Unfortunately that doesn't work for graphics yet, for that need user space interfaces for the X server are needed. There are some potential performance benefits too: - When you have a device that cannot address the complete address range an IOMMU can remap its memory instead of bounce buffering. Remapping is likely cheaper than copying. - The IOMMU can merge sg lists into a single virtual block. This could potentially speed up SG IO when the device is slow walking SG lists. [I long ago benchmarked 5% on some block benchmark with an old MPT Fusion; but it probably depends a lot on the HBA] And you get better driver debugging because unexpected memory accesses from the devices will cause a trappable event. > > Does it slow anything down? It adds more overhead to each IO so yes. This patch: Add support for early detection and parsing of DMAR's (DMA Remapping) reported to OS via ACPI tables. DMA remapping(DMAR) devices support enables independent address translations for Direct Memory Access(DMA) from Devices. These DMA remapping devices are reported via ACPI tables and includes pci device scope covered by these DMA remapping device. For detailed info on the specification of "Intel(R) Virtualization Technology for Directed I/O Architecture" please see http://www.intel.com/technology/virtualization/index.htm Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: Andi Kleen <ak@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Muli Ben-Yehuda <muli@il.ibm.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Ashok Raj <ashok.raj@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Christoph Lameter <clameter@sgi.com> Cc: Greg KH <greg@kroah.com> Cc: Len Brown <lenb@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-22 07:41:41 +08:00
#endif /* __DMAR_H__ */