[PATCH v6 2/9] irqchip/gic-v3-its: Align shared ITS allocations to the CoCo shared granule size
From: "Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>
Date: 2026-09-04 10:35:13
Also in:
kvmarm, linux-coco, linux-iommu, lkml
Subsystem:
arm generic interrupt controller drivers, irqchip drivers, the rest · Maintainers:
Marc Zyngier, Thomas Gleixner, Linus Torvalds
ITS tables allocated by the coco guest are shared with the hypervisor. These allocations must satisfy the host shared-buffer granule size so that the full converted range is safe for host access. Allocate ITS pages using a size rounded up to the shared granule size and use the same allocation order when encrypting, decrypting and freeing the memory. Also grow the ITT cache in shared-granule sized chunks instead of assuming PAGE_SIZE is sufficient. Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> --- drivers/irqchip/irq-gic-v3-its.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index e9807af23537..98d8fccbf0f2 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c@@ -216,6 +216,7 @@ static struct page *its_alloc_pages_node(int node, gfp_t gfp, struct page *page; int ret = 0; + order = get_order(mem_cc_align_to_shared_granule(PAGE_SIZE << order)); page = alloc_pages_node(node, gfp | gfp_flags_quirk, order); if (!page)
@@ -241,6 +242,8 @@ static struct page *its_alloc_pages(gfp_t gfp, unsigned int order) static void its_free_pages(void *addr, unsigned int order) { + + order = get_order(mem_cc_align_to_shared_granule(PAGE_SIZE << order)); /* * If the memory cannot be encrypted again then we must leak the pages. * set_memory_encrypted() will already have WARNed.
@@ -272,7 +275,8 @@ static void *itt_alloc_pool(int node, int size) if (!page) break; - gen_pool_add(itt_pool, (unsigned long)page_address(page), PAGE_SIZE, node); + gen_pool_add(itt_pool, (unsigned long)page_address(page), + mem_cc_align_to_shared_granule(PAGE_SIZE), node); } while (!addr); return (void *)addr;
--
2.43.0