Here several things need be done:
- If iommu is pre-enabled in a normal kernel, just disable it and print
warning.
- If failed to copy dev table of old kernel, continue to proceed as
it does in normal kernel.
- 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 <b...@redhat.com>
---
drivers/iommu/amd_iommu_init.c | 51 ++++++++++++++++++++++++++++++++++++------
1 file changed, 44 insertions(+), 7 deletions(-)
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index c58f091ce232..aa9b5918d11f 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"
@@ -1489,9 +1490,12 @@ 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);
+ }
ret = init_iommu_from_acpi(iommu, h);
if (ret)
@@ -1986,8 +1990,7 @@ 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)
{
@@ -2128,9 +2131,43 @@ static void early_enable_iommu(struct amd_iommu *iommu)
static void early_enable_iommus(void)
{
struct amd_iommu *iommu;
+ bool is_pre_enabled = false;
- for_each_iommu(iommu)
- early_enable_iommu(iommu);
+ for_each_iommu(iommu) {
+ if (translation_pre_enabled(iommu)) {
+ is_pre_enabled = true;
+ break;
+ }
+ }
+
+ if (!is_pre_enabled) {
+ for_each_iommu(iommu)
+ early_enable_iommu(iommu);
+ } else {
+ pr_warn("Translation is already enabled - trying to copy
translation structures\n");
+ if (copy_dev_tables()) {
+ pr_err("Failed to copy DEV table from previous
kernel.\n");
+ /*
+ * If failed to copy dev tables from old kernel,
continue to proceed
+ * as it does in normal kernel.
+ */
+ for_each_iommu(iommu) {
+ clear_translation_pre_enabled(iommu);
+ early_enable_iommu(iommu);
+ }
+ } else {
+ pr_info("Copied DEV table from previous kernel.\n");
+ 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
