On 28/11/2025 10:58, Harry Ramsey wrote:
> From: Penny Zheng <[email protected]>
>
> In MPU systems, we implement map_domain_page()/unmap_domain_page()
> through mapping the domain page with a MPU region on demand.
What prevents you from implementing the remaining few helpers?
~Michal
>
> Signed-off-by: Penny Zheng <[email protected]>
> Signed-off-by: Wei Chen <[email protected]>
> Signed-off-by: Luca Fancellu <[email protected]>
> Signed-off-by: Harry Ramsey <[email protected]>
> ---
> xen/arch/arm/Kconfig | 1 +
> xen/arch/arm/mpu/Makefile | 1 +
> xen/arch/arm/mpu/domain-page.c | 53 ++++++++++++++++++++++++++++++++++
> 3 files changed, 55 insertions(+)
> create mode 100644 xen/arch/arm/mpu/domain-page.c
>
> diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
> index a5c111e08e..dac9a16c28 100644
> --- a/xen/arch/arm/Kconfig
> +++ b/xen/arch/arm/Kconfig
> @@ -91,6 +91,7 @@ config MMU
>
> config MPU
> bool "MPU" if UNSUPPORTED
> + select ARCH_MAP_DOMAIN_PAGE if ARM_64
> select ARM_SECURE_STATE if ARM_64
> select STATIC_MEMORY
> help
> diff --git a/xen/arch/arm/mpu/Makefile b/xen/arch/arm/mpu/Makefile
> index 4963c8b550..940297af3f 100644
> --- a/xen/arch/arm/mpu/Makefile
> +++ b/xen/arch/arm/mpu/Makefile
> @@ -1,5 +1,6 @@
> obj-$(CONFIG_ARM_32) += arm32/
> obj-$(CONFIG_ARM_64) += arm64/
> +obj-$(CONFIG_ARM_64) += domain-page.o
> obj-y += mm.o
> obj-y += p2m.o
> obj-y += setup.init.o
> diff --git a/xen/arch/arm/mpu/domain-page.c b/xen/arch/arm/mpu/domain-page.c
> new file mode 100644
> index 0000000000..9248053ff5
> --- /dev/null
> +++ b/xen/arch/arm/mpu/domain-page.c
> @@ -0,0 +1,53 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#include <xen/bug.h>
> +#include <xen/domain_page.h>
> +#include <xen/mm.h>
> +#include <xen/mm-frame.h>
> +#include <xen/types.h>
> +
> +void *map_domain_page_global(mfn_t mfn)
> +{
> + BUG_ON("unimplemented");
> + return NULL;
> +}
> +
> +/* Map a page of domheap memory */
> +void *map_domain_page(mfn_t mfn)
> +{
> + paddr_t pa = mfn_to_maddr(mfn);
> +
> + if ( map_pages_to_xen((unsigned long)pa, mfn, 1, PAGE_HYPERVISOR_RW) )
> + return NULL;
> +
> + return maddr_to_virt(pa);
> +}
> +
> +/* Release a mapping taken with map_domain_page() */
> +void unmap_domain_page(const void *ptr)
> +{
> + paddr_t base = virt_to_maddr(ptr);
> +
> + if ( destroy_entire_xen_mapping(base) )
> + panic("Failed to unmap domain page\n");
> +}
> +
> +mfn_t domain_page_map_to_mfn(const void *ptr)
> +{
> + BUG_ON("unimplemented");
> + return INVALID_MFN;
> +}
> +
> +void unmap_domain_page_global(const void *va)
> +{
> + BUG_ON("unimplemented");
> +}
> +
> +/*
> + * Local variables:
> + * mode: C
> + * c-file-style: "BSD"
> + * c-basic-offset: 4
> + * indent-tabs-mode: nil
> + * End:
> + */
