From: Luca Fancellu <[email protected]> HAS_VMAP is not enabled on MPU systems, but the vmap functions are used in places across common code. In order to keep the existing code and maintain correct functionality, implement the `vmap_contig` and `vunmap` functions for MPU systems.
Introduce a helper function `destroy_entire_xen_mapping` to aid with unmapping an entire region when only the start address is known. Signed-off-by: Luca Fancellu <[email protected]> Signed-off-by: Harry Ramsey <[email protected]> --- xen/arch/arm/include/asm/mpu/mm.h | 11 +++++ xen/arch/arm/mpu/mm.c | 67 +++++++++++++++++++++++++------ xen/arch/arm/mpu/vmap.c | 14 +++++-- 3 files changed, 77 insertions(+), 15 deletions(-) diff --git a/xen/arch/arm/include/asm/mpu/mm.h b/xen/arch/arm/include/asm/mpu/mm.h index e1ded6521d..83ee0e59ca 100644 --- a/xen/arch/arm/include/asm/mpu/mm.h +++ b/xen/arch/arm/include/asm/mpu/mm.h @@ -111,6 +111,17 @@ pr_t pr_of_addr(paddr_t base, paddr_t limit, unsigned int flags); int mpumap_contains_region(pr_t *table, uint8_t nr_regions, paddr_t base, paddr_t limit, uint8_t *index); + +/* + * Destroys and frees (if reference count is 0) an entire xen mapping on MPU + * systems where only the start address is known. + * + * @param s Start address of memory region to be destroyed. + * + * @return: 0 on success, negative on error. + */ +int destroy_entire_xen_mapping(paddr_t s); + #endif /* __ARM_MPU_MM_H__ */ /* diff --git a/xen/arch/arm/mpu/mm.c b/xen/arch/arm/mpu/mm.c index 687dec3bc6..29d8e7ff11 100644 --- a/xen/arch/arm/mpu/mm.c +++ b/xen/arch/arm/mpu/mm.c @@ -290,6 +290,35 @@ static void disable_mpu_region_from_index(uint8_t index) write_protection_region(&xen_mpumap[index], index); } +/* + * Free a xen_mpumap entry given the index. A mpu region is actually disabled + * when the refcount is 0 and the region type is MPUMAP_REGION_FOUND. + * + * @param idx Index of the mpumap entry. + * @param region_found_type Either MPUMAP_REGION_FOUND or MPUMAP_REGION_INCLUSIVE. + * @return 0 on success, otherwise negative on error. + */ +static int xen_mpumap_free_entry(uint8_t idx, int region_found_type) +{ + ASSERT(spin_is_locked(&xen_mpumap_lock)); + ASSERT(idx != INVALID_REGION_IDX); + + if ( xen_mpumap[idx].refcount == 0 ) + { + if ( MPUMAP_REGION_FOUND == region_found_type ) + disable_mpu_region_from_index(idx); + else + { + printk(XENLOG_ERR "Cannot remove a partial region\n"); + return -EINVAL; + } + } + else + xen_mpumap[idx].refcount -= 1; + + return 0; +} + /* * Update the entry in the MPU memory region mapping table (xen_mpumap) for the * given memory range and flags, creating one if none exists. @@ -357,18 +386,7 @@ static int xen_mpumap_update_entry(paddr_t base, paddr_t limit, return -EINVAL; } - if ( xen_mpumap[idx].refcount == 0 ) - { - if ( MPUMAP_REGION_FOUND == rc ) - disable_mpu_region_from_index(idx); - else - { - printk("Cannot remove a partial region\n"); - return -EINVAL; - } - } - else - xen_mpumap[idx].refcount -= 1; + return xen_mpumap_free_entry(idx, rc); } return 0; @@ -418,6 +436,31 @@ int destroy_xen_mappings(unsigned long s, unsigned long e) return xen_mpumap_update(s, e, 0); } +int destroy_entire_xen_mapping(paddr_t s) +{ + int rc; + uint8_t idx; + + ASSERT(IS_ALIGNED(s, PAGE_SIZE)); + + spin_lock(&xen_mpumap_lock); + + rc = mpumap_contains_region(xen_mpumap, max_mpu_regions, s, s + PAGE_SIZE, + &idx); + if ( rc == MPUMAP_REGION_NOTFOUND ) + { + printk(XENLOG_ERR "Cannot remove entry that does not exist"); + rc = -EINVAL; + } + + /* As we are unmapping entire region use MPUMAP_REGION_FOUND instead */ + rc = xen_mpumap_free_entry(idx, MPUMAP_REGION_FOUND); + + spin_unlock(&xen_mpumap_lock); + + return rc; +} + int map_pages_to_xen(unsigned long virt, mfn_t mfn, unsigned long nr_mfns, unsigned int flags) { diff --git a/xen/arch/arm/mpu/vmap.c b/xen/arch/arm/mpu/vmap.c index f977b79cd4..d3037ae98a 100644 --- a/xen/arch/arm/mpu/vmap.c +++ b/xen/arch/arm/mpu/vmap.c @@ -1,19 +1,27 @@ /* SPDX-License-Identifier: GPL-2.0-only */ #include <xen/bug.h> +#include <xen/mm.h> #include <xen/mm-frame.h> #include <xen/types.h> #include <xen/vmap.h> void *vmap_contig(mfn_t mfn, unsigned int nr) { - BUG_ON("unimplemented"); - return NULL; + paddr_t base = mfn_to_maddr(mfn); + + if ( map_pages_to_xen(base, mfn, nr, PAGE_HYPERVISOR ) ) + return NULL; + + return maddr_to_virt(base); } void vunmap(const void *va) { - BUG_ON("unimplemented"); + paddr_t base = virt_to_maddr(va); + + if ( destroy_entire_xen_mapping(base) ) + panic("Failed to vunmap region\n"); } /* -- 2.43.0
