[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH 3/5] arm/mpu: Implement transient mapping
From: Luca Fancellu <luca.fancellu@xxxxxxx> Add a scheme to distinguish transient MPU regions, to identify MPU regions which will be mapped for a short period of time. Signed-off-by: Luca Fancellu <luca.fancellu@xxxxxxx> Signed-off-by: Hari Limaye <hari.limaye@xxxxxxx> --- xen/arch/arm/include/asm/arm32/mpu.h | 2 ++ xen/arch/arm/include/asm/arm64/mpu.h | 2 ++ xen/arch/arm/include/asm/mpu/mm.h | 14 +++++++++++++- xen/arch/arm/include/asm/mpu/regions.inc | 19 +++++++++++++++++-- xen/arch/arm/mpu/mm.c | 23 ++++++++++++++--------- 5 files changed, 48 insertions(+), 12 deletions(-) diff --git a/xen/arch/arm/include/asm/arm32/mpu.h b/xen/arch/arm/include/asm/arm32/mpu.h index 0a6930b3a0..9906d98809 100644 --- a/xen/arch/arm/include/asm/arm32/mpu.h +++ b/xen/arch/arm/include/asm/arm32/mpu.h @@ -39,6 +39,8 @@ typedef union { typedef struct { prbar_t prbar; prlar_t prlar; + bool transient; + uint8_t pad[7]; /* Pad structure to 16 Bytes */ } pr_t; #endif /* __ASSEMBLY__ */ diff --git a/xen/arch/arm/include/asm/arm64/mpu.h b/xen/arch/arm/include/asm/arm64/mpu.h index f0ce344e78..1d1843eda0 100644 --- a/xen/arch/arm/include/asm/arm64/mpu.h +++ b/xen/arch/arm/include/asm/arm64/mpu.h @@ -38,6 +38,8 @@ typedef union { typedef struct { prbar_t prbar; prlar_t prlar; + bool transient; + uint8_t pad[15]; /* Pad structure to 32 Bytes */ } pr_t; #endif /* __ASSEMBLY__ */ diff --git a/xen/arch/arm/include/asm/mpu/mm.h b/xen/arch/arm/include/asm/mpu/mm.h index c32fac8905..56ca411af4 100644 --- a/xen/arch/arm/include/asm/mpu/mm.h +++ b/xen/arch/arm/include/asm/mpu/mm.h @@ -60,6 +60,16 @@ static inline void context_sync_mpu(void) isb(); } +static inline bool region_is_transient(pr_t *pr) +{ + return pr->transient; +} + +static inline void region_set_transient(pr_t *pr, bool transient) +{ + pr->transient = transient; +} + /* * The following API requires context_sync_mpu() after being used to modify MPU * regions: @@ -80,9 +90,11 @@ void write_protection_region(const pr_t *pr_write, uint8_t sel); * @param base Base address of the range to map (inclusive). * @param limit Limit address of the range to map (exclusive). * @param flags Flags for the memory range to map. + * @param transient True for a temporary mapping, otherwise False. * @return 0 on success, negative on error. */ -int xen_mpumap_update(paddr_t base, paddr_t limit, unsigned int flags); +int xen_mpumap_update(paddr_t base, paddr_t limit, unsigned int flags, + bool transient); /* * Creates a pr_t structure describing a protection region. diff --git a/xen/arch/arm/include/asm/mpu/regions.inc b/xen/arch/arm/include/asm/mpu/regions.inc index 23fead3b21..f9892fe3d8 100644 --- a/xen/arch/arm/include/asm/mpu/regions.inc +++ b/xen/arch/arm/include/asm/mpu/regions.inc @@ -14,19 +14,31 @@ #define PRLAR_ELx_EN 0x1 #ifdef CONFIG_ARM_64 -#define XEN_MPUMAP_ENTRY_SHIFT 0x4 /* 16 byte structure */ +#define XEN_MPUMAP_ENTRY_SHIFT 0x5 /* 32 byte structure */ +#define XEN_MPUMAP_ENTRY_ZERO_OFFSET 0x10 /* {PRBAR, PRLAR} is 16 bytes */ .macro store_pair reg1, reg2, dst stp \reg1, \reg2, [\dst] .endm +.macro zero_pair dst, offset, tmp1, tmp2 + stp xzr, xzr, [\dst, \offset] +.endm + #else -#define XEN_MPUMAP_ENTRY_SHIFT 0x3 /* 8 byte structure */ +#define XEN_MPUMAP_ENTRY_SHIFT 0x4 /* 16 byte structure */ +#define XEN_MPUMAP_ENTRY_ZERO_OFFSET 0x8 /* {PRBAR, PRLAR} is 8 bytes */ .macro store_pair reg1, reg2, dst strd \reg1, \reg2, [\dst] .endm +.macro zero_pair dst, offset, tmp1, tmp2 + mov \tmp1, #0 + mov \tmp2, #0 + strd \tmp1, \tmp2, [\dst, \offset] +.endm + #endif /* @@ -97,6 +109,9 @@ 3: + /* Clear the rest of the xen_mpumap entry. Clobbers prbar and prlar. */ + zero_pair \base, #XEN_MPUMAP_ENTRY_ZERO_OFFSET, \prbar, \prlar + add \sel, \sel, #1 1: diff --git a/xen/arch/arm/mpu/mm.c b/xen/arch/arm/mpu/mm.c index 0b05103180..38474bcfa2 100644 --- a/xen/arch/arm/mpu/mm.c +++ b/xen/arch/arm/mpu/mm.c @@ -251,13 +251,14 @@ static void disable_mpu_region_from_index(uint8_t index) * Update the entry in the MPU memory region mapping table (xen_mpumap) for the * given memory range and flags, creating one if none exists. * - * @param base Base address (inclusive). - * @param limit Limit address (exclusive). - * @param flags Region attributes (a combination of PAGE_HYPERVISOR_XXX) + * @param base Base address (inclusive). + * @param limit Limit address (exclusive). + * @param flags Region attributes (a combination of PAGE_HYPERVISOR_XXX) + * @param transient True for a temporary mapping, otherwise False. * @return 0 on success, otherwise negative on error. */ static int xen_mpumap_update_entry(paddr_t base, paddr_t limit, - unsigned int flags) + unsigned int flags, bool transient) { bool flags_has_page_present; uint8_t idx; @@ -297,6 +298,7 @@ static int xen_mpumap_update_entry(paddr_t base, paddr_t limit, return -ENOENT; xen_mpumap[idx] = pr_of_addr(base, limit, flags); + region_set_transient(&xen_mpumap[idx], transient); write_protection_region(&xen_mpumap[idx], idx); } @@ -316,7 +318,8 @@ static int xen_mpumap_update_entry(paddr_t base, paddr_t limit, return 0; } -int xen_mpumap_update(paddr_t base, paddr_t limit, unsigned int flags) +int xen_mpumap_update(paddr_t base, paddr_t limit, unsigned int flags, + bool transient) { int rc; @@ -342,7 +345,7 @@ int xen_mpumap_update(paddr_t base, paddr_t limit, unsigned int flags) spin_lock(&xen_mpumap_lock); - rc = xen_mpumap_update_entry(base, limit, flags); + rc = xen_mpumap_update_entry(base, limit, flags, transient); if ( !rc ) context_sync_mpu(); @@ -357,14 +360,15 @@ int destroy_xen_mappings(unsigned long s, unsigned long e) ASSERT(IS_ALIGNED(e, PAGE_SIZE)); ASSERT(s < e); - return xen_mpumap_update(s, e, 0); + return xen_mpumap_update(s, e, 0, false); } int map_pages_to_xen(unsigned long virt, mfn_t mfn, unsigned long nr_mfns, unsigned int flags) { /* MPU systems have no translation, ma == va, so pass virt directly */ - return xen_mpumap_update(virt, mfn_to_maddr(mfn_add(mfn, nr_mfns)), flags); + return xen_mpumap_update(virt, mfn_to_maddr(mfn_add(mfn, nr_mfns)), flags, + false); } /* @@ -385,7 +389,8 @@ static void __init setup_staticheap_mappings(void) paddr_t bank_end = bank_start + bank_size; /* Map static heap with one MPU protection region */ - if ( xen_mpumap_update(bank_start, bank_end, PAGE_HYPERVISOR) ) + if ( xen_mpumap_update(bank_start, bank_end, PAGE_HYPERVISOR, + false) ) panic("Failed to map static heap\n"); break; -- 2.34.1
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