[PATCH AUTOSEL 5.4 50/73] iommu/vt-d: Fix RCU-list bugs in intel_iommu_init()

[PATCH AUTOSEL 5.4 50/73] iommu/vt-d: Fix RCU-list bugs in intel_iommu_init()

[Sasha Levin]

From: Qian Cai <cai@lca.pw>

[ Upstream commit 2d48ea0efb8887ebba3e3720bb5b738aced4e574 ]

There are several places traverse RCU-list without holding any lock in
intel_iommu_init(). Fix them by acquiring dmar_global_lock.

 WARNING: suspicious RCU usage
 -----------------------------
 drivers/iommu/intel-iommu.c:5216 RCU-list traversed in non-reader section!!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 1
 no locks held by swapper/0/1.

 Call Trace:
  dump_stack+0xa0/0xea
  lockdep_rcu_suspicious+0x102/0x10b
  intel_iommu_init+0x947/0xb13
  pci_iommu_init+0x26/0x62
  do_one_initcall+0xfe/0x500
  kernel_init_freeable+0x45a/0x4f8
  kernel_init+0x11/0x139
  ret_from_fork+0x3a/0x50
 DMAR: Intel(R) Virtualization Technology for Directed I/O

Fixes: d8190dc63886 ("iommu/vt-d: Enable DMA remapping after rmrr mapped")
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/intel-iommu.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 760a242d0801d..9b3d169c6ff53 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5023,6 +5023,7 @@ int __init intel_iommu_init(void)
 
 	init_iommu_pm_ops();
 
+	down_read(&dmar_global_lock);
 	for_each_active_iommu(iommu, drhd) {
 		iommu_device_sysfs_add(&iommu->iommu, NULL,
 				       intel_iommu_groups,
@@ -5030,6 +5031,7 @@ int __init intel_iommu_init(void)
 		iommu_device_set_ops(&iommu->iommu, &intel_iommu_ops);
 		iommu_device_register(&iommu->iommu);
 	}
+	up_read(&dmar_global_lock);
 
 	bus_set_iommu(&pci_bus_type, &intel_iommu_ops);
 	if (si_domain && !hw_pass_through)
@@ -5040,7 +5042,6 @@ int __init intel_iommu_init(void)
 	down_read(&dmar_global_lock);
 	if (probe_acpi_namespace_devices())
 		pr_warn("ACPI name space devices didn't probe correctly\n");
-	up_read(&dmar_global_lock);
 
 	/* Finally, we enable the DMA remapping hardware. */
 	for_each_iommu(iommu, drhd) {
@@ -5049,6 +5050,8 @@ int __init intel_iommu_init(void)
 
 		iommu_disable_protect_mem_regions(iommu);
 	}
+	up_read(&dmar_global_lock);
+
 	pr_info("Intel(R) Virtualization Technology for Directed I/O\n");
 
 	intel_iommu_enabled = 1;
-- 
2.20.1

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[PATCH AUTOSEL 5.4 51/73] iommu/vt-d: Silence RCU-list debugging warnings

[Sasha Levin]

From: Qian Cai <cai@lca.pw>

[ Upstream commit f5152416528c2295f35dd9c9bd4fb27c4032413d ]

Similar to the commit 02d715b4a818 ("iommu/vt-d: Fix RCU list debugging
warnings"), there are several other places that call
list_for_each_entry_rcu() outside of an RCU read side critical section
but with dmar_global_lock held. Silence those false positives as well.

 drivers/iommu/intel-iommu.c:4288 RCU-list traversed in non-reader section!!
 1 lock held by swapper/0/1:
  #0: ffffffff935892c8 (dmar_global_lock){+.+.}, at: intel_iommu_init+0x1ad/0xb97

 drivers/iommu/dmar.c:366 RCU-list traversed in non-reader section!!
 1 lock held by swapper/0/1:
  #0: ffffffff935892c8 (dmar_global_lock){+.+.}, at: intel_iommu_init+0x125/0xb97

 drivers/iommu/intel-iommu.c:5057 RCU-list traversed in non-reader section!!
 1 lock held by swapper/0/1:
  #0: ffffffffa71892c8 (dmar_global_lock){++++}, at: intel_iommu_init+0x61a/0xb13

Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/dmar.c | 3 ++-
 include/linux/dmar.h | 6 ++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 7196cabafb252..6ec5da4d028f9 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -363,7 +363,8 @@ dmar_find_dmaru(struct acpi_dmar_hardware_unit *drhd)
 {
 	struct dmar_drhd_unit *dmaru;
 
-	list_for_each_entry_rcu(dmaru, &dmar_drhd_units, list)
+	list_for_each_entry_rcu(dmaru, &dmar_drhd_units, list,
+				dmar_rcu_check())
 		if (dmaru->segment == drhd->segment &&
 		    dmaru->reg_base_addr == drhd->address)
 			return dmaru;
diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index a7cf3599d9a1c..e0d52e9358c9c 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -73,11 +73,13 @@ extern struct list_head dmar_drhd_units;
 	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)		\
+	list_for_each_entry_rcu(drhd, &dmar_drhd_units, list,		\
+				dmar_rcu_check())			\
 		if (drhd->ignored) {} else
 
 #define for_each_active_iommu(i, drhd)					\
-	list_for_each_entry_rcu(drhd, &dmar_drhd_units, list)		\
+	list_for_each_entry_rcu(drhd, &dmar_drhd_units, list,		\
+				dmar_rcu_check())			\
 		if (i=drhd->iommu, drhd->ignored) {} else
 
 #define for_each_iommu(i, drhd)						\
-- 
2.20.1

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[PATCH AUTOSEL 5.4 67/73] iommu/vt-d: quirk_ioat_snb_local_iommu: replace WARN_TAINT with pr_warn + add_taint

[Sasha Levin]

From: Hans de Goede <hdegoede@redhat.com>

[ Upstream commit 81ee85d0462410de8eeeec1b9761941fd6ed8c7b ]

Quoting from the comment describing the WARN functions in
include/asm-generic/bug.h:

 * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
 * significant kernel issues that need prompt attention if they should ever
 * appear at runtime.
 *
 * Do not use these macros when checking for invalid external inputs

The (buggy) firmware tables which the dmar code was calling WARN_TAINT
for really are invalid external inputs. They are not under the kernel's
control and the issues in them cannot be fixed by a kernel update.
So logging a backtrace, which invites bug reports to be filed about this,
is not helpful.

Fixes: 556ab45f9a77 ("ioat2: catch and recover from broken vtd configurations v6")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200309182510.373875-1-hdegoede@redhat.com
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=701847
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/intel-iommu.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 9b3d169c6ff53..be39363244389 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4129,10 +4129,11 @@ static void quirk_ioat_snb_local_iommu(struct pci_dev *pdev)
 
 	/* we know that the this iommu should be at offset 0xa000 from vtbar */
 	drhd = dmar_find_matched_drhd_unit(pdev);
-	if (WARN_TAINT_ONCE(!drhd || drhd->reg_base_addr - vtbar != 0xa000,
-			    TAINT_FIRMWARE_WORKAROUND,
-			    "BIOS assigned incorrect VT-d unit for Intel(R) QuickData Technology device\n"))
+	if (!drhd || drhd->reg_base_addr - vtbar != 0xa000) {
+		pr_warn_once(FW_BUG "BIOS assigned incorrect VT-d unit for Intel(R) QuickData Technology device\n");
+		add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
 		pdev->dev.archdata.iommu = DUMMY_DEVICE_DOMAIN_INFO;
+	}
 }
 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_SNB, quirk_ioat_snb_local_iommu);
 
-- 
2.20.1

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[PATCH AUTOSEL 5.4 68/73] iommu/vt-d: Fix debugfs register reads

[Sasha Levin]

From: Megha Dey <megha.dey@linux.intel.com>

[ Upstream commit ba3b01d7a6f4ab9f8a0557044c9a7678f64ae070 ]

Commit 6825d3ea6cde ("iommu/vt-d: Add debugfs support to show register
contents") dumps the register contents for all IOMMU devices.

Currently, a 64 bit read(dmar_readq) is done for all the IOMMU registers,
even though some of the registers are 32 bits, which is incorrect.

Use the correct read function variant (dmar_readl/dmar_readq) while
reading the contents of 32/64 bit registers respectively.

Signed-off-by: Megha Dey <megha.dey@linux.intel.com>
Link: https://lore.kernel.org/r/1583784587-26126-2-git-send-email-megha.dey@linux.intel.com
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/intel-iommu-debugfs.c | 40 ++++++++++++++++++-----------
 include/linux/intel-iommu.h         |  2 ++
 2 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/drivers/iommu/intel-iommu-debugfs.c b/drivers/iommu/intel-iommu-debugfs.c
index 471f05d452e01..80378c10dd77a 100644
--- a/drivers/iommu/intel-iommu-debugfs.c
+++ b/drivers/iommu/intel-iommu-debugfs.c
@@ -32,38 +32,42 @@ struct iommu_regset {
 
 #define IOMMU_REGSET_ENTRY(_reg_)					\
 	{ DMAR_##_reg_##_REG, __stringify(_reg_) }
-static const struct iommu_regset iommu_regs[] = {
+
+static const struct iommu_regset iommu_regs_32[] = {
 	IOMMU_REGSET_ENTRY(VER),
-	IOMMU_REGSET_ENTRY(CAP),
-	IOMMU_REGSET_ENTRY(ECAP),
 	IOMMU_REGSET_ENTRY(GCMD),
 	IOMMU_REGSET_ENTRY(GSTS),
-	IOMMU_REGSET_ENTRY(RTADDR),
-	IOMMU_REGSET_ENTRY(CCMD),
 	IOMMU_REGSET_ENTRY(FSTS),
 	IOMMU_REGSET_ENTRY(FECTL),
 	IOMMU_REGSET_ENTRY(FEDATA),
 	IOMMU_REGSET_ENTRY(FEADDR),
 	IOMMU_REGSET_ENTRY(FEUADDR),
-	IOMMU_REGSET_ENTRY(AFLOG),
 	IOMMU_REGSET_ENTRY(PMEN),
 	IOMMU_REGSET_ENTRY(PLMBASE),
 	IOMMU_REGSET_ENTRY(PLMLIMIT),
+	IOMMU_REGSET_ENTRY(ICS),
+	IOMMU_REGSET_ENTRY(PRS),
+	IOMMU_REGSET_ENTRY(PECTL),
+	IOMMU_REGSET_ENTRY(PEDATA),
+	IOMMU_REGSET_ENTRY(PEADDR),
+	IOMMU_REGSET_ENTRY(PEUADDR),
+};
+
+static const struct iommu_regset iommu_regs_64[] = {
+	IOMMU_REGSET_ENTRY(CAP),
+	IOMMU_REGSET_ENTRY(ECAP),
+	IOMMU_REGSET_ENTRY(RTADDR),
+	IOMMU_REGSET_ENTRY(CCMD),
+	IOMMU_REGSET_ENTRY(AFLOG),
 	IOMMU_REGSET_ENTRY(PHMBASE),
 	IOMMU_REGSET_ENTRY(PHMLIMIT),
 	IOMMU_REGSET_ENTRY(IQH),
 	IOMMU_REGSET_ENTRY(IQT),
 	IOMMU_REGSET_ENTRY(IQA),
-	IOMMU_REGSET_ENTRY(ICS),
 	IOMMU_REGSET_ENTRY(IRTA),
 	IOMMU_REGSET_ENTRY(PQH),
 	IOMMU_REGSET_ENTRY(PQT),
 	IOMMU_REGSET_ENTRY(PQA),
-	IOMMU_REGSET_ENTRY(PRS),
-	IOMMU_REGSET_ENTRY(PECTL),
-	IOMMU_REGSET_ENTRY(PEDATA),
-	IOMMU_REGSET_ENTRY(PEADDR),
-	IOMMU_REGSET_ENTRY(PEUADDR),
 	IOMMU_REGSET_ENTRY(MTRRCAP),
 	IOMMU_REGSET_ENTRY(MTRRDEF),
 	IOMMU_REGSET_ENTRY(MTRR_FIX64K_00000),
@@ -126,10 +130,16 @@ static int iommu_regset_show(struct seq_file *m, void *unused)
 		 * by adding the offset to the pointer (virtual address).
 		 */
 		raw_spin_lock_irqsave(&iommu->register_lock, flag);
-		for (i = 0 ; i < ARRAY_SIZE(iommu_regs); i++) {
-			value = dmar_readq(iommu->reg + iommu_regs[i].offset);
+		for (i = 0 ; i < ARRAY_SIZE(iommu_regs_32); i++) {
+			value = dmar_readl(iommu->reg + iommu_regs_32[i].offset);
+			seq_printf(m, "%-16s\t0x%02x\t\t0x%016llx\n",
+				   iommu_regs_32[i].regs, iommu_regs_32[i].offset,
+				   value);
+		}
+		for (i = 0 ; i < ARRAY_SIZE(iommu_regs_64); i++) {
+			value = dmar_readq(iommu->reg + iommu_regs_64[i].offset);
 			seq_printf(m, "%-16s\t0x%02x\t\t0x%016llx\n",
-				   iommu_regs[i].regs, iommu_regs[i].offset,
+				   iommu_regs_64[i].regs, iommu_regs_64[i].offset,
 				   value);
 		}
 		raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 6d8bf4bdf240d..1e5dad8b8e59b 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -120,6 +120,8 @@
 
 #define dmar_readq(a) readq(a)
 #define dmar_writeq(a,v) writeq(v,a)
+#define dmar_readl(a) readl(a)
+#define dmar_writel(a, v) writel(v, a)
 
 #define DMAR_VER_MAJOR(v)		(((v) & 0xf0) >> 4)
 #define DMAR_VER_MINOR(v)		((v) & 0x0f)
-- 
2.20.1

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[PATCH AUTOSEL 5.4 70/73] iommu/vt-d: Fix the wrong printing in RHSA parsing

[Sasha Levin]

From: Zhenzhong Duan <zhenzhong.duan@gmail.com>

[ Upstream commit b0bb0c22c4db623f2e7b1a471596fbf1c22c6dc5 ]

When base address in RHSA structure doesn't match base address in
each DRHD structure, the base address in last DRHD is printed out.

This doesn't make sense when there are multiple DRHD units, fix it
by printing the buggy RHSA's base address.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@gmail.com>
Fixes: fd0c8894893cb ("intel-iommu: Set a more specific taint flag for invalid BIOS DMAR tables")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/dmar.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 6ec5da4d028f9..aa15155b9401f 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -476,7 +476,7 @@ static int dmar_parse_one_rhsa(struct acpi_dmar_header *header, void *arg)
 		1, TAINT_FIRMWARE_WORKAROUND,
 		"Your BIOS is broken; RHSA refers to non-existent DMAR unit at %llx\n"
 		"BIOS vendor: %s; Ver: %s; Product Version: %s\n",
-		drhd->reg_base_addr,
+		rhsa->base_address,
 		dmi_get_system_info(DMI_BIOS_VENDOR),
 		dmi_get_system_info(DMI_BIOS_VERSION),
 		dmi_get_system_info(DMI_PRODUCT_VERSION));
-- 
2.20.1

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[PATCH AUTOSEL 5.4 71/73] iommu/vt-d: Ignore devices with out-of-spec domain number

[Sasha Levin]

From: Daniel Drake <drake@endlessm.com>

[ Upstream commit da72a379b2ec0bad3eb265787f7008bead0b040c ]

VMD subdevices are created with a PCI domain ID of 0x10000 or
higher.

These subdevices are also handled like all other PCI devices by
dmar_pci_bus_notifier().

However, when dmar_alloc_pci_notify_info() take records of such devices,
it will truncate the domain ID to a u16 value (in info->seg).
The device at (e.g.) 10000:00:02.0 is then treated by the DMAR code as if
it is 0000:00:02.0.

In the unlucky event that a real device also exists at 0000:00:02.0 and
also has a device-specific entry in the DMAR table,
dmar_insert_dev_scope() will crash on:
   BUG_ON(i >= devices_cnt);

That's basically a sanity check that only one PCI device matches a
single DMAR entry; in this case we seem to have two matching devices.

Fix this by ignoring devices that have a domain number higher than
what can be looked up in the DMAR table.

This problem was carefully diagnosed by Jian-Hong Pan.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Daniel Drake <drake@endlessm.com>
Fixes: 59ce0515cdaf3 ("iommu/vt-d: Update DRHD/RMRR/ATSR device scope caches when PCI hotplug happens")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/dmar.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index aa15155b9401f..34e705d3b6bb6 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -28,6 +28,7 @@
 #include <linux/slab.h>
 #include <linux/iommu.h>
 #include <linux/numa.h>
+#include <linux/limits.h>
 #include <asm/irq_remapping.h>
 #include <asm/iommu_table.h>
 
@@ -128,6 +129,13 @@ dmar_alloc_pci_notify_info(struct pci_dev *dev, unsigned long event)
 
 	BUG_ON(dev->is_virtfn);
 
+	/*
+	 * Ignore devices that have a domain number higher than what can
+	 * be looked up in DMAR, e.g. VMD subdevices with domain 0x10000
+	 */
+	if (pci_domain_nr(dev->bus) > U16_MAX)
+		return NULL;
+
 	/* Only generate path[] for device addition event */
 	if (event == BUS_NOTIFY_ADD_DEVICE)
 		for (tmp = dev; tmp; tmp = tmp->bus->self)
-- 
2.20.1

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[PATCH AUTOSEL 5.4 72/73] iommu/amd: Fix IOMMU AVIC not properly update the is_run bit in IRTE

[Sasha Levin]

From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>

[ Upstream commit 730ad0ede130015a773229573559e97ba0943065 ]

Commit b9c6ff94e43a ("iommu/amd: Re-factor guest virtual APIC
(de-)activation code") accidentally left out the ir_data pointer when
calling modity_irte_ga(), which causes the function amd_iommu_update_ga()
to return prematurely due to struct amd_ir_data.ref is NULL and
the "is_run" bit of IRTE does not get updated properly.

This results in bad I/O performance since IOMMU AVIC always generate GA Log
entry and notify IOMMU driver and KVM when it receives interrupt from the
PCI pass-through device instead of directly inject interrupt to the vCPU.

Fixes by passing ir_data when calling modify_irte_ga() as done previously.

Fixes: b9c6ff94e43a ("iommu/amd: Re-factor guest virtual APIC (de-)activation code")
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/amd_iommu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 8bd5d608a82c2..bc77714983421 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -4421,7 +4421,7 @@ int amd_iommu_activate_guest_mode(void *data)
 	entry->lo.fields_vapic.ga_tag      = ir_data->ga_tag;
 
 	return modify_irte_ga(ir_data->irq_2_irte.devid,
-			      ir_data->irq_2_irte.index, entry, NULL);
+			      ir_data->irq_2_irte.index, entry, ir_data);
 }
 EXPORT_SYMBOL(amd_iommu_activate_guest_mode);
 
@@ -4447,7 +4447,7 @@ int amd_iommu_deactivate_guest_mode(void *data)
 				APICID_TO_IRTE_DEST_HI(cfg->dest_apicid);
 
 	return modify_irte_ga(ir_data->irq_2_irte.devid,
-			      ir_data->irq_2_irte.index, entry, NULL);
+			      ir_data->irq_2_irte.index, entry, ir_data);
 }
 EXPORT_SYMBOL(amd_iommu_deactivate_guest_mode);
 
-- 
2.20.1

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[PATCH AUTOSEL 5.4 73/73] iommu/vt-d: Populate debugfs if IOMMUs are detected

[Sasha Levin]

From: Megha Dey <megha.dey@linux.intel.com>

[ Upstream commit 1da8347d8505c137fb07ff06bbcd3f2bf37409bc ]

Currently, the intel iommu debugfs directory(/sys/kernel/debug/iommu/intel)
gets populated only when DMA remapping is enabled (dmar_disabled = 0)
irrespective of whether interrupt remapping is enabled or not.

Instead, populate the intel iommu debugfs directory if any IOMMUs are
detected.

Cc: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: ee2636b8670b1 ("iommu/vt-d: Enable base Intel IOMMU debugfs support")
Signed-off-by: Megha Dey <megha.dey@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/intel-iommu-debugfs.c | 11 ++++++++++-
 drivers/iommu/intel-iommu.c         |  4 +++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/intel-iommu-debugfs.c b/drivers/iommu/intel-iommu-debugfs.c
index 80378c10dd77a..bdf095e9dbe03 100644
--- a/drivers/iommu/intel-iommu-debugfs.c
+++ b/drivers/iommu/intel-iommu-debugfs.c
@@ -281,9 +281,16 @@ static int dmar_translation_struct_show(struct seq_file *m, void *unused)
 {
 	struct dmar_drhd_unit *drhd;
 	struct intel_iommu *iommu;
+	u32 sts;
 
 	rcu_read_lock();
 	for_each_active_iommu(iommu, drhd) {
+		sts = dmar_readl(iommu->reg + DMAR_GSTS_REG);
+		if (!(sts & DMA_GSTS_TES)) {
+			seq_printf(m, "DMA Remapping is not enabled on %s\n",
+				   iommu->name);
+			continue;
+		}
 		root_tbl_walk(m, iommu);
 		seq_putc(m, '\n');
 	}
@@ -353,6 +360,7 @@ static int ir_translation_struct_show(struct seq_file *m, void *unused)
 	struct dmar_drhd_unit *drhd;
 	struct intel_iommu *iommu;
 	u64 irta;
+	u32 sts;
 
 	rcu_read_lock();
 	for_each_active_iommu(iommu, drhd) {
@@ -362,7 +370,8 @@ static int ir_translation_struct_show(struct seq_file *m, void *unused)
 		seq_printf(m, "Remapped Interrupt supported on IOMMU: %s\n",
 			   iommu->name);
 
-		if (iommu->ir_table) {
+		sts = dmar_readl(iommu->reg + DMAR_GSTS_REG);
+		if (iommu->ir_table && (sts & DMA_GSTS_IRES)) {
 			irta = virt_to_phys(iommu->ir_table->base);
 			seq_printf(m, " IR table address:%llx\n", irta);
 			ir_tbl_remap_entry_show(m, iommu);
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index be39363244389..ef38e98b5bceb 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4961,6 +4961,9 @@ int __init intel_iommu_init(void)
 
 	down_write(&dmar_global_lock);
 
+	if (!no_iommu)
+		intel_iommu_debugfs_init();
+
 	if (no_iommu || dmar_disabled) {
 		/*
 		 * We exit the function here to ensure IOMMU's remapping and
@@ -5056,7 +5059,6 @@ int __init intel_iommu_init(void)
 	pr_info("Intel(R) Virtualization Technology for Directed I/O\n");
 
 	intel_iommu_enabled = 1;
-	intel_iommu_debugfs_init();
 
 	return 0;
 
-- 
2.20.1

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