At the moment, when mapping a device into Stage-2 for a guest,
we override whatever the guest uses by forcing a device memory
type in Stage-2.
While this is not exactly wrong, this isn't really the "spirit" of
the architecture. The hardware shouldn't have to cope for a broken
guest mapping to a device as normal memory.
As such, let's get rid of the memory type overrides, and map
everything as PAGE_S2 in Stage-2. This simplifies the code and
let the guest do its own thing, whether it is stupid or not.
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
arch/arm/include/asm/pgtable.h | 2 --
arch/arm/kvm/mmu.c | 2 +-
arch/arm/mm/mmu.c | 6 ++----
3 files changed, 3 insertions(+), 7 deletions(-)
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 9bcd262..c3410a8 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -81,7 +81,6 @@ extern pgprot_t pgprot_user;
extern pgprot_t pgprot_kernel;
extern pgprot_t pgprot_hyp_device;
extern pgprot_t pgprot_s2;
-extern pgprot_t pgprot_s2_device;
#define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b))
@@ -97,7 +96,6 @@ extern pgprot_t pgprot_s2_device;
#define PAGE_HYP _MOD_PROT(pgprot_kernel, L_PTE_HYP)
#define PAGE_HYP_DEVICE _MOD_PROT(pgprot_hyp_device, L_PTE_HYP)
#define PAGE_S2 _MOD_PROT(pgprot_s2, L_PTE_S2_RDONLY)
-#define PAGE_S2_DEVICE _MOD_PROT(pgprot_s2_device, L_PTE_USER | L_PTE_S2_RDONLY)
#define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN | L_PTE_NONE)
#define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 693d16c..f2a8416 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -495,7 +495,7 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
pfn = __phys_to_pfn(pa);
for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
- pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);
+ pte_t pte = pfn_pte(pfn, PAGE_S2);
kvm_set_s2pte_writable(&pte);
ret = mmu_topup_memory_cache(&cache, 2, 2);
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index e0d8565..bc001f5 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -60,7 +60,6 @@ pgprot_t pgprot_user;
pgprot_t pgprot_kernel;
pgprot_t pgprot_hyp_device;
pgprot_t pgprot_s2;
-pgprot_t pgprot_s2_device;
EXPORT_SYMBOL(pgprot_user);
EXPORT_SYMBOL(pgprot_kernel);
@@ -343,7 +342,7 @@ static void __init build_mem_type_table(void)
struct cachepolicy *cp;
unsigned int cr = get_cr();
pteval_t user_pgprot, kern_pgprot, vecs_pgprot;
- pteval_t hyp_device_pgprot, s2_pgprot, s2_device_pgprot;
+ pteval_t hyp_device_pgprot, s2_pgprot;
int cpu_arch = cpu_architecture();
int i;
@@ -456,7 +455,7 @@ static void __init build_mem_type_table(void)
cp = &cache_policies[cachepolicy];
vecs_pgprot = kern_pgprot = user_pgprot = cp->pte;
s2_pgprot = cp->pte_s2;
- hyp_device_pgprot = s2_device_pgprot = mem_types[MT_DEVICE].prot_pte;
+ hyp_device_pgprot = mem_types[MT_DEVICE].prot_pte;
/*
* ARMv6 and above have extended page tables.
@@ -536,7 +535,6 @@ static void __init build_mem_type_table(void)
pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
L_PTE_DIRTY | kern_pgprot);
pgprot_s2 = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | s2_pgprot);
- pgprot_s2_device = __pgprot(s2_device_pgprot);
pgprot_hyp_device = __pgprot(hyp_device_pgprot);
mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask;
--
1.8.2.3
--
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