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 <b...@redhat.com> --- drivers/iommu/amd_iommu_init.c | 57 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 50 insertions(+), 7 deletions(-) diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c index ab6794539527..e3d8af9d9636 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" @@ -1498,9 +1499,12 @@ 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) @@ -1995,8 +1999,7 @@ 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) { @@ -2137,9 +2140,49 @@ static void early_enable_iommu(struct amd_iommu *iommu) static void early_enable_iommus(void) { struct amd_iommu *iommu; + bool is_pre_disabled = false; - for_each_iommu(iommu) - early_enable_iommu(iommu); + for_each_iommu(iommu) { + if (!translation_pre_enabled(iommu)) { + is_pre_disabled = true; + break; + } + } + + if (is_pre_disabled) { + for_each_iommu(iommu) + early_enable_iommu(iommu); + } else { + pr_warn("Translation is already enabled - trying to copy translation structures\n"); + if (copy_device_table()) { + 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. + */ + 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 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu