| Message ID | 20240830090821.23105-1-ayan.kumar.halder@amd.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v5] xen: make VMAP support in MMU system only | expand |
On 30.08.2024 11:08, Ayan Kumar Halder wrote: > From: Penny Zheng <penny.zheng@arm.com> > > Introduce CONFIG_HAS_VMAP which is selected by the architectures that > use MMU. vm_init() does not do anything if CONFIG_HAS_VMAP is not > enabled. > > HAS_VMAP is widely used in ALTERNATIVE feature to remap a range of > memory with new memory attributes. Since this is highly dependent on > virtual address translation, we choose to make HAS_VMAP selected by > MMU. And ALTERNATIVE depends on HAS_VMAP. > > At the moment, the users of HARDEN_BRANCH_PREDICTOR requires to use the > vmap() to update the exceptions vectors. While it might be possible to > rework the code, it is believed that speculative attackes would be > difficult to exploit on non-MMU because the software is tightly > controlled. So for now make HARDEN_BRANCH_PREDICTOR to depend on the > MMU. > > Also took the opportunity to remove "#ifdef VMAP_VIRT_START .. endif" > from vmap.c. Instead vmap.c is compiled when HAS_VMAP is enabled. Thus, > HAS_VMAP is now enabled from x86, ppc and riscv architectures as all of > them use MMU and has VMAP_VIRT_START defined. > > Signed-off-by: Penny Zheng <penny.zheng@arm.com> > Signed-off-by: Wei Chen <wei.chen@arm.com> > Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@amd.com> > Acked-by: Julien Grall <jgrall@amazon.com> Acked-by: Jan Beulich <jbeulich@suse.com>
diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig index 21d03d9f44..323c967361 100644 --- a/xen/arch/arm/Kconfig +++ b/xen/arch/arm/Kconfig @@ -12,7 +12,7 @@ config ARM_64 config ARM def_bool y select FUNCTION_ALIGNMENT_4B - select HAS_ALTERNATIVE + select HAS_ALTERNATIVE if HAS_VMAP select HAS_DEVICE_TREE select HAS_PASSTHROUGH select HAS_UBSAN @@ -61,6 +61,7 @@ config PADDR_BITS config MMU def_bool y select HAS_PMAP + select HAS_VMAP source "arch/Kconfig" @@ -171,6 +172,7 @@ config ARM_SSBD config HARDEN_BRANCH_PREDICTOR bool "Harden the branch predictor against aliasing attacks" if EXPERT + depends on MMU default y help Speculation attacks against some high-performance processors rely on diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c index 961d3ea670..71ebaa77ca 100644 --- a/xen/arch/arm/setup.c +++ b/xen/arch/arm/setup.c @@ -446,7 +446,9 @@ void asmlinkage __init start_xen(unsigned long fdt_paddr) * It needs to be called after do_initcalls to be able to use * stop_machine (tasklets initialized via an initcall). */ +#ifdef CONFIG_HAS_ALTERNATIVE apply_alternatives_all(); +#endif enable_errata_workarounds(); enable_cpu_features(); diff --git a/xen/arch/ppc/Kconfig b/xen/arch/ppc/Kconfig index f6a77a8200..6db575a48d 100644 --- a/xen/arch/ppc/Kconfig +++ b/xen/arch/ppc/Kconfig @@ -2,6 +2,7 @@ config PPC def_bool y select FUNCTION_ALIGNMENT_4B select HAS_DEVICE_TREE + select HAS_VMAP config PPC64 def_bool y diff --git a/xen/arch/riscv/Kconfig b/xen/arch/riscv/Kconfig index 259eea8d3b..7a113c7774 100644 --- a/xen/arch/riscv/Kconfig +++ b/xen/arch/riscv/Kconfig @@ -3,6 +3,7 @@ config RISCV select FUNCTION_ALIGNMENT_16B select GENERIC_BUG_FRAME select HAS_DEVICE_TREE + select HAS_VMAP config RISCV_64 def_bool y diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig index d0aaf359eb..dee8db45e8 100644 --- a/xen/arch/x86/Kconfig +++ b/xen/arch/x86/Kconfig @@ -29,6 +29,7 @@ config X86 select HAS_PIRQ select HAS_SCHED_GRANULARITY select HAS_UBSAN + select HAS_VMAP select HAS_VPCI if HVM select NEEDS_LIBELF diff --git a/xen/common/Kconfig b/xen/common/Kconfig index 565ceda741..90268d9249 100644 --- a/xen/common/Kconfig +++ b/xen/common/Kconfig @@ -83,6 +83,9 @@ config HAS_SCHED_GRANULARITY config HAS_UBSAN bool +config HAS_VMAP + bool + config MEM_ACCESS_ALWAYS_ON bool diff --git a/xen/common/Makefile b/xen/common/Makefile index 7e66802a9e..fc52e0857d 100644 --- a/xen/common/Makefile +++ b/xen/common/Makefile @@ -52,7 +52,7 @@ obj-$(CONFIG_TRACEBUFFER) += trace.o obj-y += version.o obj-y += virtual_region.o obj-y += vm_event.o -obj-y += vmap.o +obj-$(CONFIG_HAS_VMAP) += vmap.o obj-y += vsprintf.o obj-y += wait.o obj-bin-y += warning.init.o diff --git a/xen/common/vmap.c b/xen/common/vmap.c index ced9cbf26f..47225fecc0 100644 --- a/xen/common/vmap.c +++ b/xen/common/vmap.c @@ -1,4 +1,3 @@ -#ifdef VMAP_VIRT_START #include <xen/bitmap.h> #include <xen/sections.h> #include <xen/init.h> @@ -427,4 +426,3 @@ void *_xvrealloc(void *va, size_t size, unsigned int align) return ptr; } -#endif diff --git a/xen/include/xen/vmap.h b/xen/include/xen/vmap.h index fdae37e950..c1dd7ac22f 100644 --- a/xen/include/xen/vmap.h +++ b/xen/include/xen/vmap.h @@ -141,7 +141,9 @@ void *arch_vmap_virt_end(void); /* Initialises the VMAP_DEFAULT virtual range */ static inline void vm_init(void) { +#ifdef CONFIG_HAS_VMAP vm_init_type(VMAP_DEFAULT, (void *)VMAP_VIRT_START, arch_vmap_virt_end()); +#endif } #endif /* __XEN_VMAP_H__ */