irqchip/gic-v3-its: Mark some in-memory data structures as 'decrypted'
The GICv3 ITS driver allocates memory for its tables using alloc_pages()
and performs explicit cache maintenance if necessary. On systems such
as those running pKVM, where the memory encryption API is implemented,
memory shared with the ITS must first be transitioned to the "decrypted"
state, as it would be if allocated via the DMA API.
Allow pKVM guests to interact with an ITS emulation by ensuring that the
shared pages are decrypted at the point of allocation and encrypted
again upon free().
Signed-off-by: Will Deacon <will@kernel.org>
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index eb0882d..4559b8d 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -27,6 +27,7 @@
#include <linux/of_pci.h>
#include <linux/of_platform.h>
#include <linux/percpu.h>
+#include <linux/set_memory.h>
#include <linux/slab.h>
#include <linux/syscore_ops.h>
@@ -2166,6 +2167,7 @@
/* Make sure the GIC will observe the written configuration */
gic_flush_dcache_to_poc(va, LPI_PROPBASE_SZ);
+ set_memory_decrypted((unsigned long)va, LPI_PROPBASE_SZ >> PAGE_SHIFT);
}
static struct page *its_allocate_prop_table(gfp_t gfp_flags)
@@ -2183,8 +2185,10 @@
static void its_free_prop_table(struct page *prop_page)
{
- free_pages((unsigned long)page_address(prop_page),
- get_order(LPI_PROPBASE_SZ));
+ unsigned long va = (unsigned long)page_address(prop_page);
+
+ set_memory_encrypted(va, LPI_PROPBASE_SZ >> PAGE_SHIFT);
+ free_pages(va, get_order(LPI_PROPBASE_SZ));
}
static bool gic_check_reserved_range(phys_addr_t addr, unsigned long size)
@@ -2377,6 +2381,8 @@
return -ENXIO;
}
+ set_memory_decrypted((unsigned long)base,
+ PAGE_ORDER_TO_SIZE(order) >> PAGE_SHIFT);
baser->order = order;
baser->base = base;
baser->psz = psz;
@@ -2512,8 +2518,12 @@
for (i = 0; i < GITS_BASER_NR_REGS; i++) {
if (its->tables[i].base) {
- free_pages((unsigned long)its->tables[i].base,
- its->tables[i].order);
+ unsigned long base = (unsigned long)its->tables[i].base;
+ u32 order = its->tables[i].order;
+ u32 npages = PAGE_ORDER_TO_SIZE(order) >> PAGE_SHIFT;
+
+ set_memory_encrypted(base, npages);
+ free_pages(base, order);
its->tables[i].base = NULL;
}
}
@@ -2934,6 +2944,7 @@
static struct page *its_allocate_pending_table(gfp_t gfp_flags)
{
struct page *pend_page;
+ void *va;
pend_page = alloc_pages(gfp_flags | __GFP_ZERO,
get_order(LPI_PENDBASE_SZ));
@@ -2941,14 +2952,19 @@
return NULL;
/* Make sure the GIC will observe the zero-ed page */
- gic_flush_dcache_to_poc(page_address(pend_page), LPI_PENDBASE_SZ);
+ va = page_address(pend_page);
+ gic_flush_dcache_to_poc(va, LPI_PENDBASE_SZ);
+ set_memory_decrypted((unsigned long)va, LPI_PENDBASE_SZ >> PAGE_SHIFT);
return pend_page;
}
static void its_free_pending_table(struct page *pt)
{
- free_pages((unsigned long)page_address(pt), get_order(LPI_PENDBASE_SZ));
+ unsigned long va = (unsigned long)page_address(pt);
+
+ set_memory_encrypted(va, LPI_PENDBASE_SZ >> PAGE_SHIFT);
+ free_pages(va, get_order(LPI_PENDBASE_SZ));
}
/*
@@ -3268,14 +3284,20 @@
/* Allocate memory for 2nd level table */
if (!table[idx]) {
+ void *l2addr;
+
page = alloc_pages_node(its->numa_node, GFP_KERNEL | __GFP_ZERO,
get_order(baser->psz));
if (!page)
return false;
+ l2addr = page_address(page);
+ set_memory_decrypted((unsigned long)l2addr,
+ baser->psz >> PAGE_SHIFT);
+
/* Flush Lvl2 table to PoC if hw doesn't support coherency */
if (!(baser->val & GITS_BASER_SHAREABILITY_MASK))
- gic_flush_dcache_to_poc(page_address(page), baser->psz);
+ gic_flush_dcache_to_poc(l2addr, baser->psz);
table[idx] = cpu_to_le64(page_to_phys(page) | GITS_BASER_VALID);
@@ -5043,6 +5065,8 @@
its->fwnode_handle = handle;
its->get_msi_base = its_irq_get_msi_base;
its->msi_domain_flags = IRQ_DOMAIN_FLAG_MSI_REMAP;
+ set_memory_decrypted((unsigned long)its->cmd_base,
+ ITS_CMD_QUEUE_SZ >> PAGE_SHIFT);
its_enable_quirks(its);
@@ -5099,6 +5123,8 @@
out_free_tables:
its_free_tables(its);
out_free_cmd:
+ set_memory_encrypted((unsigned long)its->cmd_base,
+ ITS_CMD_QUEUE_SZ >> PAGE_SHIFT);
free_pages((unsigned long)its->cmd_base, get_order(ITS_CMD_QUEUE_SZ));
out_unmap_sgir:
if (its->sgir_base)
