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Message-Id: <1502267624-7066-7-git-send-email-bhe@redhat.com>
Date: Wed, 9 Aug 2017 16:33:38 +0800
From: Baoquan He <bhe@...hat.com>
To: jroedel@...e.de
Cc: iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
Baoquan He <bhe@...hat.com>
Subject: [PATCH v10 06/12] iommu/amd: copy old trans table from old kernel
Here several things need be done:
- If iommu is pre-enabled in a normal kernel, just disable it and print
warning.
- If any one of IOMMUs is not pre-enabled in kdump kernel, just continue
as it does in normal kernel.
- If failed to copy dev table of old kernel, continue to proceed as
it does in normal kernel.
- Only if all IOMMUs are pre-enabled and copy dev table is done well, free
the dev table allocated in early_amd_iommu_init() and make amd_iommu_dev_table
point to the copied one.
- Disable and Re-enable event/cmd buffer, install the copied DTE table
to reg, and detect and enable guest vapic.
- Flush all caches
Signed-off-by: Baoquan He <bhe@...hat.com>
---
v9->v10:
Add global variable amd_iommu_pre_enabled to mark if all IOMMUs are
pre-enabled. If any one is not pre-enabled, just set it as false.
Check amd_iommu_pre_enabled in copy_device_table(), return directly from
copy_device_table() if it's false.
Judge by the return value of copy_device_table() to decide if it will go
through the normal handling or special handling after copy.
drivers/iommu/amd_iommu_init.c | 59 ++++++++++++++++++++++++++++++++++++------
1 file changed, 51 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index e2857204d32a..959c25d997e1 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -37,6 +37,7 @@
#include <asm/io_apic.h>
#include <asm/irq_remapping.h>
+#include <linux/crash_dump.h>
#include "amd_iommu_proto.h"
#include "amd_iommu_types.h"
#include "irq_remapping.h"
@@ -262,6 +263,8 @@ static int amd_iommu_enable_interrupts(void);
static int __init iommu_go_to_state(enum iommu_init_state state);
static void init_device_table_dma(void);
+static bool __initdata amd_iommu_pre_enabled = true;
+
bool translation_pre_enabled(struct amd_iommu *iommu)
{
return (iommu->flags & AMD_IOMMU_FLAG_TRANS_PRE_ENABLED);
@@ -857,6 +860,8 @@ static bool copy_device_table(void)
u16 dom_id, dte_v;
gfp_t gfp_flag;
+ if (!amd_iommu_pre_enabled)
+ return false;
pr_warn("Translation is already enabled - trying to copy translation structures\n");
for_each_iommu(iommu) {
@@ -1496,9 +1501,14 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
iommu->int_enabled = false;
init_translation_status(iommu);
-
- if (translation_pre_enabled(iommu))
- pr_warn("Translation is already enabled - trying to copy translation structures\n");
+ if (translation_pre_enabled(iommu) && !is_kdump_kernel()) {
+ iommu_disable(iommu);
+ clear_translation_pre_enabled(iommu);
+ pr_warn("Translation was enabled for IOMMU:%d but we are not in kdump mode\n",
+ iommu->index);
+ }
+ if (amd_iommu_pre_enabled)
+ amd_iommu_pre_enabled = translation_pre_enabled(iommu);
ret = init_iommu_from_acpi(iommu, h);
if (ret)
@@ -1993,8 +2003,7 @@ static int __init init_memory_definitions(struct acpi_table_header *table)
}
/*
- * Init the device table to not allow DMA access for devices and
- * suppress all page faults
+ * Init the device table to not allow DMA access for devices
*/
static void init_device_table_dma(void)
{
@@ -2130,14 +2139,48 @@ static void early_enable_iommu(struct amd_iommu *iommu)
/*
* This function finally enables all IOMMUs found in the system after
- * they have been initialized
+ * they have been initialized.
+ *
+ * Or if in kdump kernel and IOMMUs are all pre-enabled, try to copy
+ * the old content of device table entries. Not this case or copy failed,
+ * just continue as normal kernel does.
*/
static void early_enable_iommus(void)
{
struct amd_iommu *iommu;
- for_each_iommu(iommu)
- early_enable_iommu(iommu);
+
+ if (!copy_device_table()) {
+ /*
+ * If come here because of failure in copying device table from old
+ * kernel with all IOMMUs enabled, print error message and try to
+ * free allocated old_dev_tbl_cpy.
+ */
+ if (amd_iommu_pre_enabled)
+ pr_err("Failed to copy DEV table from previous kernel.\n");
+ if (old_dev_tbl_cpy != NULL)
+ free_pages((unsigned long)old_dev_tbl_cpy,
+ get_order(dev_table_size));
+
+ for_each_iommu(iommu) {
+ clear_translation_pre_enabled(iommu);
+ early_enable_iommu(iommu);
+ }
+ } else {
+ pr_info("Copied DEV table from previous kernel.\n");
+ free_pages((unsigned long)amd_iommu_dev_table,
+ get_order(dev_table_size));
+ amd_iommu_dev_table = old_dev_tbl_cpy;
+ for_each_iommu(iommu) {
+ iommu_disable_command_buffer(iommu);
+ iommu_disable_event_buffer(iommu);
+ iommu_enable_command_buffer(iommu);
+ iommu_enable_event_buffer(iommu);
+ iommu_enable_ga(iommu);
+ iommu_set_device_table(iommu);
+ iommu_flush_all_caches(iommu);
+ }
+ }
#ifdef CONFIG_IRQ_REMAP
if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))
--
2.5.5
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