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author | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2013-12-11 20:58:42 +0400 |
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committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-12-13 20:20:30 +0400 |
commit | c1d15f5c8bc1170dafe16e988e55437245966dfe (patch) | |
tree | bb1c364882addcaa8ac053ed12ae7a501f54a3be | |
parent | 380108d891acf8db5cf0d477176c7ed2b62b7928 (diff) | |
download | linux-c1d15f5c8bc1170dafe16e988e55437245966dfe.tar.xz |
xen/balloon: Seperate the auto-translate logic properly (v2)
The auto-xlat logic vs the non-xlat means that we don't need to for
auto-xlat guests (like PVH, HVM or ARM):
- use P2M
- use scratch page.
However the code in increase_reservation does modify the p2m for
auto_translate guests, but not in decrease_reservation.
Fix that by avoiding any p2m modifications in both increase_reservation
and decrease_reservation for auto_translated guests.
And also avoid allocating or using scratch pages for auto_translated guests.
Lastly, since !auto-xlat is really another way of saying 'xen_pv'
remove the redundant 'xen_pv_domain' check.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
[v2: Updated the description]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
-rw-r--r-- | drivers/xen/balloon.c | 63 |
1 files changed, 34 insertions, 29 deletions
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 55ea73f7c70b..4c02e2b94103 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -350,17 +350,19 @@ static enum bp_state increase_reservation(unsigned long nr_pages) pfn = page_to_pfn(page); - set_phys_to_machine(pfn, frame_list[i]); - #ifdef CONFIG_XEN_HAVE_PVMMU - /* Link back into the page tables if not highmem. */ - if (xen_pv_domain() && !PageHighMem(page)) { - int ret; - ret = HYPERVISOR_update_va_mapping( - (unsigned long)__va(pfn << PAGE_SHIFT), - mfn_pte(frame_list[i], PAGE_KERNEL), - 0); - BUG_ON(ret); + if (!xen_feature(XENFEAT_auto_translated_physmap)) { + set_phys_to_machine(pfn, frame_list[i]); + + /* Link back into the page tables if not highmem. */ + if (!PageHighMem(page)) { + int ret; + ret = HYPERVISOR_update_va_mapping( + (unsigned long)__va(pfn << PAGE_SHIFT), + mfn_pte(frame_list[i], PAGE_KERNEL), + 0); + BUG_ON(ret); + } } #endif @@ -378,7 +380,6 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) enum bp_state state = BP_DONE; unsigned long pfn, i; struct page *page; - struct page *scratch_page; int ret; struct xen_memory_reservation reservation = { .address_bits = 0, @@ -411,27 +412,29 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) scrub_page(page); +#ifdef CONFIG_XEN_HAVE_PVMMU /* * Ballooned out frames are effectively replaced with * a scratch frame. Ensure direct mappings and the * p2m are consistent. */ - scratch_page = get_balloon_scratch_page(); -#ifdef CONFIG_XEN_HAVE_PVMMU - if (xen_pv_domain() && !PageHighMem(page)) { - ret = HYPERVISOR_update_va_mapping( - (unsigned long)__va(pfn << PAGE_SHIFT), - pfn_pte(page_to_pfn(scratch_page), - PAGE_KERNEL_RO), 0); - BUG_ON(ret); - } -#endif if (!xen_feature(XENFEAT_auto_translated_physmap)) { unsigned long p; + struct page *scratch_page = get_balloon_scratch_page(); + + if (!PageHighMem(page)) { + ret = HYPERVISOR_update_va_mapping( + (unsigned long)__va(pfn << PAGE_SHIFT), + pfn_pte(page_to_pfn(scratch_page), + PAGE_KERNEL_RO), 0); + BUG_ON(ret); + } p = page_to_pfn(scratch_page); __set_phys_to_machine(pfn, pfn_to_mfn(p)); + + put_balloon_scratch_page(); } - put_balloon_scratch_page(); +#endif balloon_append(pfn_to_page(pfn)); } @@ -627,15 +630,17 @@ static int __init balloon_init(void) if (!xen_domain()) return -ENODEV; - for_each_online_cpu(cpu) - { - per_cpu(balloon_scratch_page, cpu) = alloc_page(GFP_KERNEL); - if (per_cpu(balloon_scratch_page, cpu) == NULL) { - pr_warn("Failed to allocate balloon_scratch_page for cpu %d\n", cpu); - return -ENOMEM; + if (!xen_feature(XENFEAT_auto_translated_physmap)) { + for_each_online_cpu(cpu) + { + per_cpu(balloon_scratch_page, cpu) = alloc_page(GFP_KERNEL); + if (per_cpu(balloon_scratch_page, cpu) == NULL) { + pr_warn("Failed to allocate balloon_scratch_page for cpu %d\n", cpu); + return -ENOMEM; + } } + register_cpu_notifier(&balloon_cpu_notifier); } - register_cpu_notifier(&balloon_cpu_notifier); pr_info("Initialising balloon driver\n"); |