xen/x86: Use memblock_reserve for sensitive areas. (59b29440) · Commits · 戴 / test

arch/x86/xen/enlighten.c

+48 −0

Original line number	Diff line number	Diff line
		@@ -998,7 +998,54 @@ static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)

		return ret;
		}
		/*
		* If the MFN is not in the m2p (provided to us by the hypervisor) this
		* function won't do anything. In practice this means that the XenBus
		* MFN won't be available for the initial domain. */
		static void __init xen_reserve_mfn(unsigned long mfn)
		{
		unsigned long pfn;

		if (!mfn)
		return;
		pfn = mfn_to_pfn(mfn);
		if (phys_to_machine_mapping_valid(pfn))
		memblock_reserve(PFN_PHYS(pfn), PAGE_SIZE);
		}
		static void __init xen_reserve_internals(void)
		{
		unsigned long size;

		if (!xen_pv_domain())
		return;

		/* xen_start_info does not exist in the M2P, hence can't use
		* xen_reserve_mfn. */
		memblock_reserve(__pa(xen_start_info), PAGE_SIZE);

		xen_reserve_mfn(PFN_DOWN(xen_start_info->shared_info));
		xen_reserve_mfn(xen_start_info->store_mfn);

		if (!xen_initial_domain())
		xen_reserve_mfn(xen_start_info->console.domU.mfn);

		if (xen_feature(XENFEAT_auto_translated_physmap))
		return;

		/*
		* ALIGN up to compensate for the p2m_page pointing to an array that
		* can partially filled (look in xen_build_dynamic_phys_to_machine).
		*/

		size = PAGE_ALIGN(xen_start_info->nr_pages * sizeof(unsigned long));

		/* We could use xen_reserve_mfn here, but would end up looping quite
		* a lot (and call memblock_reserve for each PAGE), so lets just use
		* the easy way and reserve it wholesale. */
		memblock_reserve(__pa(xen_start_info->mfn_list), size);

		/* The pagetables are reserved in mmu.c */
		}
		void xen_setup_shared_info(void)
		{
		if (!xen_feature(XENFEAT_auto_translated_physmap)) {
		@@ -1362,6 +1409,7 @@ asmlinkage void __init xen_start_kernel(void)
		xen_raw_console_write("mapping kernel into physical memory\n");
		pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);

		xen_reserve_internals();
		/* Allocate and initialize top and mid mfn levels for p2m structure */
		xen_build_mfn_list_list();

arch/x86/xen/p2m.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -388,6 +388,11 @@ void __init xen_build_dynamic_phys_to_machine(void)
		}

		m2p_override_init();

		/* NOTE: We cannot call memblock_reserve here for the mfn_list as there
		* isn't enough pieces to make it work (for one - we are still using the
		* Xen provided pagetable). Do it later in xen_reserve_internals.
		*/
		}

		unsigned long get_phys_to_machine(unsigned long pfn)

arch/x86/xen/setup.c

+0 −9

Original line number	Diff line number	Diff line
		@@ -424,15 +424,6 @@ char * __init xen_memory_setup(void)
		e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
		E820_RESERVED);

		/*
		* Reserve Xen bits:
		* - mfn_list
		* - xen_start_info
		* See comment above "struct start_info" in <xen/interface/xen.h>
		*/
		memblock_reserve(__pa(xen_start_info->mfn_list),
		xen_start_info->pt_base - xen_start_info->mfn_list);

		sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);

		return "Xen";

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