diff options
author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2012-07-19 10:23:47 -0400 |
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committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2012-08-21 14:44:50 -0400 |
commit | 59b294403e9814e7c1154043567f0d71bac7a511 (patch) | |
tree | 42f84556415209884f19ab58df234ae098f67c66 /arch/x86/xen/enlighten.c | |
parent | a3118beb6a8cbe77ae3342125d920205871b0717 (diff) |
xen/x86: Use memblock_reserve for sensitive areas.
instead of a big memblock_reserve. This way we can be more
selective in freeing regions (and it also makes it easier
to understand where is what).
[v1: Move the auto_translate_physmap to proper line]
[v2: Per Stefano suggestion add more comments]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'arch/x86/xen/enlighten.c')
-rw-r--r-- | arch/x86/xen/enlighten.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index ff962d4b821..e532eb50e8d 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -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(); |