diff options
| -rw-r--r-- | arch/x86/xen/enlighten.c | 60 | ||||
| -rw-r--r-- | arch/x86/xen/p2m.c | 5 | ||||
| -rw-r--r-- | arch/x86/xen/setup.c | 27 |
3 files changed, 27 insertions, 65 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 511f92d79e4a..ff962d4b821e 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -998,66 +998,7 @@ 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 unsigned long __init xen_reserve_mfn(unsigned long mfn) -{ - unsigned long pfn, end_pfn = 0; - - if (!mfn) - return end_pfn; - - pfn = mfn_to_pfn(mfn); - if (phys_to_machine_mapping_valid(pfn)) { - end_pfn = PFN_PHYS(pfn) + PAGE_SIZE; - memblock_reserve(PFN_PHYS(pfn), end_pfn); - } - return end_pfn; -} -static void __init xen_reserve_internals(void) -{ - unsigned long size; - unsigned long last_phys = 0; - - 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); - last_phys = __pa(xen_start_info) + PAGE_SIZE; - - last_phys = max(xen_reserve_mfn(PFN_DOWN(xen_start_info->shared_info)), last_phys); - last_phys = max(xen_reserve_mfn(xen_start_info->store_mfn), last_phys); - if (!xen_initial_domain()) - last_phys = max(xen_reserve_mfn(xen_start_info->console.domU.mfn), last_phys); - - 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); - last_phys = max(__pa(xen_start_info->mfn_list) + size, last_phys); - /* The pagetables are reserved in mmu.c */ - - /* Under 64-bit hypervisor with a 32-bit domain, the hypervisor - * offsets the pt_base by two pages. Hence the reservation that is done - * in mmu.c misses two pages. We correct it here if we detect this. */ - if (last_phys < __pa(xen_start_info->pt_base)) - memblock_reserve(last_phys, __pa(xen_start_info->pt_base) - last_phys); -} void xen_setup_shared_info(void) { if (!xen_feature(XENFEAT_auto_translated_physmap)) { @@ -1421,7 +1362,6 @@ 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(); diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 6a2bfa43c8a1..e4adbfbdfada 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -388,11 +388,6 @@ 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) diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 9efca750405d..740517be4da5 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -424,6 +424,33 @@ 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> + * We tried to make the the memblock_reserve more selective so + * that it would be clear what region is reserved. Sadly we ran + * in the problem wherein on a 64-bit hypervisor with a 32-bit + * initial domain, the pt_base has the cr3 value which is not + * neccessarily where the pagetable starts! As Jan put it: " + * Actually, the adjustment turns out to be correct: The page + * tables for a 32-on-64 dom0 get allocated in the order "first L1", + * "first L2", "first L3", so the offset to the page table base is + * indeed 2. When reading xen/include/public/xen.h's comment + * very strictly, this is not a violation (since there nothing is said + * that the first thing in the page table space is pointed to by + * pt_base; I admit that this seems to be implied though, namely + * do I think that it is implied that the page table space is the + * range [pt_base, pt_base + nt_pt_frames), whereas that + * range here indeed is [pt_base - 2, pt_base - 2 + nt_pt_frames), + * which - without a priori knowledge - the kernel would have + * difficulty to figure out)." - so lets just fall back to the + * easy way and reserve the whole region. + */ + 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"; |