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Message-Id: <1433513463-19128-9-git-send-email-joro@8bytes.org>
Date: Fri, 5 Jun 2015 16:10:54 +0200
From: Joerg Roedel <joro@...tes.org>
To: iommu@...ts.linux-foundation.org
Cc: zhen-hual@...com, bhe@...hat.com, dwmw2@...radead.org,
vgoyal@...hat.com, dyoung@...hat.com, alex.williamson@...hat.com,
ddutile@...hat.com, ishii.hironobu@...fujitsu.com,
indou.takao@...fujitsu.com, bhelgaas@...gle.com, doug.hatch@...com,
jerry.hoemann@...com, tom.vaden@...com, li.zhang6@...com,
lisa.mitchell@...com, billsumnerlinux@...il.com, rwright@...com,
linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org,
kexec@...ts.infradead.org, joro@...tes.org, jroedel@...e.de
Subject: [PATCH 08/17] iommu/vt-d: Don't reuse domain-ids from old kernel
From: Joerg Roedel <jroedel@...e.de>
Change the context table copy code to copy context
entrys one by one and check whether they are present and
mark the used domain-id as reserved in the allocation
bitmap. This way the domain-id will not be reused by new
domains allocated in the kdump kernel.
Tested-by: Baoquan He <bhe@...hat.com>
Signed-off-by: Joerg Roedel <jroedel@...e.de>
---
drivers/iommu/intel-iommu.c | 80 ++++++++++++++-------------------------------
1 file changed, 25 insertions(+), 55 deletions(-)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 2602b33..82239e3 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -367,10 +367,6 @@ static inline int first_pte_in_page(struct dma_pte *pte)
* do the same thing as crashdump kernel.
*/
-static struct context_entry *device_to_existing_context_entry(
- struct intel_iommu *iommu,
- u8 bus, u8 devfn);
-
/*
* A structure used to store the address allocated by ioremap();
* The we need to call iounmap() to free them out of spin_lock_irqsave/unlock;
@@ -2337,7 +2333,6 @@ static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw)
unsigned long flags;
u8 bus, devfn;
int did = -1; /* Default to "no domain_id supplied" */
- struct context_entry *ce = NULL;
domain = find_domain(dev);
if (domain)
@@ -2372,19 +2367,6 @@ static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw)
if (!domain)
return NULL;
- if (iommu->pre_enabled_trans) {
- /*
- * if this device had a did in the old kernel
- * use its values instead of generating new ones
- */
- ce = device_to_existing_context_entry(iommu, bus, devfn);
-
- if (ce) {
- did = context_domain_id(ce);
- gaw = agaw_to_width(context_address_width(ce));
- }
- }
-
domain->id = iommu_attach_domain_with_id(domain, iommu, did);
if (domain->id < 0) {
free_domain_mem(domain);
@@ -4931,49 +4913,37 @@ static void __init check_tylersburg_isoch(void)
vtisochctrl);
}
-static struct context_entry *device_to_existing_context_entry(
- struct intel_iommu *iommu,
- u8 bus, u8 devfn)
-{
- struct root_entry *root;
- struct context_entry *context;
- struct context_entry *ret = NULL;
- unsigned long flags;
-
- spin_lock_irqsave(&iommu->lock, flags);
- root = &iommu->root_entry[bus];
- context = get_context_addr_from_root(root);
- if (context && context_present(context+devfn))
- ret = &context[devfn];
- spin_unlock_irqrestore(&iommu->lock, flags);
- return ret;
-}
-
/*
- * Copy memory from a physically-addressed area into a virtually-addressed area
+ * Copy one context table
*/
-static int copy_from_oldmem_phys(void *to, phys_addr_t from, size_t size)
+static int copy_one_context_table(struct intel_iommu *iommu,
+ struct context_entry *ctxt_tbl,
+ phys_addr_t old_table_phys)
{
- void __iomem *virt_mem;
- unsigned long offset;
- unsigned long pfn;
+ struct context_entry __iomem *ctxt_tbl_old, ce;
+ int did, devfn;
- pfn = from >> VTD_PAGE_SHIFT;
- offset = from & (~VTD_PAGE_MASK);
+ ctxt_tbl_old = ioremap_cache(old_table_phys, VTD_PAGE_SIZE);
+ if (!ctxt_tbl_old)
+ return -ENOMEM;
- if (page_is_ram(pfn)) {
- memcpy(to, pfn_to_kaddr(pfn) + offset, size);
- } else {
- virt_mem = ioremap_cache((unsigned long)from, size);
- if (!virt_mem)
- return -ENOMEM;
+ for (devfn = 0; devfn < 256; devfn++) {
+ memcpy_fromio(&ce, &ctxt_tbl_old[devfn],
+ sizeof(struct context_entry));
- memcpy(to, virt_mem, size);
+ if (!context_present(&ce))
+ continue;
+
+ did = context_domain_id(&ce);
+ if (did >=0 && did < cap_ndoms(iommu->cap))
+ set_bit(did, iommu->domain_ids);
- iounmap(virt_mem);
+ ctxt_tbl[devfn] = ce;
}
- return size;
+ iounmap(ctxt_tbl_old);
+
+ return 0;
}
/*
@@ -5002,9 +4972,9 @@ static int copy_context_tables(struct intel_iommu *iommu,
if (!context_new_virt)
goto out_err;
- ret = copy_from_oldmem_phys(context_new_virt, context_old_phys,
- VTD_PAGE_SIZE);
- if (ret != VTD_PAGE_SIZE) {
+ ret = copy_one_context_table(iommu, context_new_virt,
+ context_old_phys);
+ if (ret) {
pr_err("Failed to copy context table for bus %d from physical address 0x%llx\n",
bus, context_old_phys);
free_pgtable_page(context_new_virt);
--
1.9.1
--
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