[PATCH 5/9] iommu/amd: Convert Event Log pointer to use struct amd_iommu_mem

From: Suravee Suthikulpanit
Date: Tue Apr 30 2024 - 11:25:56 EST


And specify the memory to be 4K-aligned when running in SNP host, and
to be decrypted when running in an SEV guest so that the VMM can access
the memory successfully.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
drivers/iommu/amd/amd_iommu_types.h | 2 +-
drivers/iommu/amd/init.c | 20 +++++++++++++-------
drivers/iommu/amd/iommu.c | 2 +-
3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index e671e9220a21..af4e9ca6414e 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -738,7 +738,7 @@ struct amd_iommu {
u32 cmd_buf_tail;

/* event buffer virtual address */
- u8 *evt_buf;
+ struct amd_iommu_mem evt_buf_mem;

/* Name for event log interrupt */
unsigned char evt_irq_name[16];
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 51861874656e..5242a9a16946 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -860,19 +860,25 @@ void *__init iommu_alloc_4k_pages(struct amd_iommu *iommu, gfp_t gfp,
/* allocates the memory where the IOMMU will log its events to */
static int __init alloc_event_buffer(struct amd_iommu *iommu)
{
- iommu->evt_buf = iommu_alloc_4k_pages(iommu, GFP_KERNEL,
- EVT_BUFFER_SIZE);
+ struct amd_iommu_mem *mem = &iommu->evt_buf_mem;

- return iommu->evt_buf ? 0 : -ENOMEM;
+ mem->modes = ALLOC_MODE_4K | ALLOC_MODE_GUEST_MEM_DECRYPT;
+ mem->order = get_order(EVT_BUFFER_SIZE);
+ mem->buf = amd_iommu_get_zeroed_mem(GFP_KERNEL, mem);
+ if (!mem->buf)
+ return -ENOMEM;
+
+ return 0;
}

static void iommu_enable_event_buffer(struct amd_iommu *iommu)
{
u64 entry;

- BUG_ON(iommu->evt_buf == NULL);
+ BUG_ON(iommu->evt_buf_mem.buf == NULL);

- entry = iommu_virt_to_phys(iommu->evt_buf) | EVT_LEN_MASK;
+ entry = amd_iommu_mem_to_phys(&iommu->evt_buf_mem);
+ entry |= EVT_LEN_MASK;

memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET,
&entry, sizeof(entry));
@@ -894,7 +900,7 @@ static void iommu_disable_event_buffer(struct amd_iommu *iommu)

static void __init free_event_buffer(struct amd_iommu *iommu)
{
- iommu_free_pages(iommu->evt_buf, get_order(EVT_BUFFER_SIZE));
+ amd_iommu_free_mem(&iommu->evt_buf_mem);
}

static void free_ga_log(struct amd_iommu *iommu)
@@ -3838,7 +3844,7 @@ int amd_iommu_snp_disable(void)
return 0;

for_each_iommu(iommu) {
- ret = iommu_make_shared(iommu->evt_buf, EVT_BUFFER_SIZE);
+ ret = iommu_make_shared(iommu->evt_buf_mem.buf, EVT_BUFFER_SIZE);
if (ret)
return ret;

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index bd29d26c8d44..4f95c726e139 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -890,7 +890,7 @@ static void iommu_poll_events(struct amd_iommu *iommu)
tail = readl(iommu->mmio_base + MMIO_EVT_TAIL_OFFSET);

while (head != tail) {
- iommu_print_event(iommu, iommu->evt_buf + head);
+ iommu_print_event(iommu, (u8 *)iommu->evt_buf_mem.buf + head);
head = (head + EVENT_ENTRY_SIZE) % EVT_BUFFER_SIZE;
}

--
2.34.1