[PATCH v4 13/13] iommu/amd: Adopt IO page table framework for AMD IOMMU v1 page table

From: Suravee Suthikulpanit
Date: Tue Dec 15 2020 - 02:37:52 EST


Switch to using IO page table framework for AMD IOMMU v1 page table.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
drivers/iommu/amd/amd_iommu.h | 1 +
drivers/iommu/amd/init.c | 2 ++
drivers/iommu/amd/iommu.c | 48 ++++++++++++++++++++++++++---------
3 files changed, 39 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
index 3770b1a4d51c..91452e0ff072 100644
--- a/drivers/iommu/amd/amd_iommu.h
+++ b/drivers/iommu/amd/amd_iommu.h
@@ -36,6 +36,7 @@ extern void amd_iommu_disable(void);
extern int amd_iommu_reenable(int);
extern int amd_iommu_enable_faulting(void);
extern int amd_iommu_guest_ir;
+extern enum io_pgtable_fmt amd_iommu_pgtable;

/* IOMMUv2 specific functions */
struct iommu_domain;
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 23a790f8f550..5fb4bea14cc4 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -147,6 +147,8 @@ struct ivmd_header {
bool amd_iommu_dump;
bool amd_iommu_irq_remap __read_mostly;

+enum io_pgtable_fmt amd_iommu_pgtable = AMD_IOMMU_V1;
+
int amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_VAPIC;
static int amd_iommu_xt_mode = IRQ_REMAP_XAPIC_MODE;

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 1f04b251f0c6..571e8806e4a1 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -31,6 +31,7 @@
#include <linux/irqdomain.h>
#include <linux/percpu.h>
#include <linux/iova.h>
+#include <linux/io-pgtable.h>
#include <asm/irq_remapping.h>
#include <asm/io_apic.h>
#include <asm/apic.h>
@@ -1901,7 +1902,7 @@ static void protection_domain_free(struct protection_domain *domain)
kfree(domain);
}

-static int protection_domain_init(struct protection_domain *domain, int mode)
+static int protection_domain_init_v1(struct protection_domain *domain, int mode)
{
u64 *pt_root = NULL;

@@ -1924,34 +1925,55 @@ static int protection_domain_init(struct protection_domain *domain, int mode)
return 0;
}

-static struct protection_domain *protection_domain_alloc(int mode)
+static struct protection_domain *protection_domain_alloc(unsigned int type)
{
+ struct io_pgtable_ops *pgtbl_ops;
struct protection_domain *domain;
+ int pgtable = amd_iommu_pgtable;
+ int mode = DEFAULT_PGTABLE_LEVEL;
+ int ret;

domain = kzalloc(sizeof(*domain), GFP_KERNEL);
if (!domain)
return NULL;

- if (protection_domain_init(domain, mode))
+ /*
+ * Force IOMMU v1 page table when iommu=pt and
+ * when allocating domain for pass-through devices.
+ */
+ if (type == IOMMU_DOMAIN_IDENTITY) {
+ pgtable = AMD_IOMMU_V1;
+ mode = PAGE_MODE_NONE;
+ } else if (type == IOMMU_DOMAIN_UNMANAGED) {
+ pgtable = AMD_IOMMU_V1;
+ }
+
+ switch (pgtable) {
+ case AMD_IOMMU_V1:
+ ret = protection_domain_init_v1(domain, mode);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ if (ret)
goto out_err;

- return domain;
+ pgtbl_ops = alloc_io_pgtable_ops(pgtable, &domain->iop.pgtbl_cfg, domain);
+ if (!pgtbl_ops)
+ goto out_err;

+ return domain;
out_err:
kfree(domain);
-
return NULL;
}

static struct iommu_domain *amd_iommu_domain_alloc(unsigned type)
{
struct protection_domain *domain;
- int mode = DEFAULT_PGTABLE_LEVEL;
-
- if (type == IOMMU_DOMAIN_IDENTITY)
- mode = PAGE_MODE_NONE;

- domain = protection_domain_alloc(mode);
+ domain = protection_domain_alloc(type);
if (!domain)
return NULL;

@@ -2070,7 +2092,8 @@ static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova,
int prot = 0;
int ret = -EINVAL;

- if (domain->iop.mode == PAGE_MODE_NONE)
+ if ((amd_iommu_pgtable == AMD_IOMMU_V1) &&
+ (domain->iop.mode == PAGE_MODE_NONE))
return -EINVAL;

if (iommu_prot & IOMMU_READ)
@@ -2093,7 +2116,8 @@ static size_t amd_iommu_unmap(struct iommu_domain *dom, unsigned long iova,
struct protection_domain *domain = to_pdomain(dom);
struct io_pgtable_ops *ops = &domain->iop.iop.ops;

- if (domain->iop.mode == PAGE_MODE_NONE)
+ if ((amd_iommu_pgtable == AMD_IOMMU_V1) &&
+ (domain->iop.mode == PAGE_MODE_NONE))
return 0;

return (ops->unmap) ? ops->unmap(ops, iova, page_size, gather) : 0;
--
2.17.1