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author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-05-24 19:24:49 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-05-24 19:24:49 +0200 |
commit | 9351f138d1dcbe504cd829abe590ba7f3387f09c (patch) | |
tree | 5b55a5ba42c0ba2d75c173452d7567c8093eb098 /arch/x86/xen | |
parent | Merge tag 'for-6.10-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kda... (diff) | |
parent | drivers/xen: Improve the late XenStore init protocol (diff) | |
download | linux-9351f138d1dcbe504cd829abe590ba7f3387f09c.tar.xz linux-9351f138d1dcbe504cd829abe590ba7f3387f09c.zip |
Merge tag 'for-linus-6.10a-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from Juergen Gross:
- a small cleanup in the drivers/xen/xenbus Makefile
- a fix of the Xen xenstore driver to improve connecting to a late
started Xenstore
- an enhancement for better support of ballooning in PVH guests
- a cleanup using try_cmpxchg() instead of open coding it
* tag 'for-linus-6.10a-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
drivers/xen: Improve the late XenStore init protocol
xen/xenbus: Use *-y instead of *-objs in Makefile
xen/x86: add extra pages to unpopulated-alloc if available
locking/x86/xen: Use try_cmpxchg() in xen_alloc_p2m_entry()
Diffstat (limited to 'arch/x86/xen')
-rw-r--r-- | arch/x86/xen/enlighten.c | 33 | ||||
-rw-r--r-- | arch/x86/xen/p2m.c | 11 |
2 files changed, 38 insertions, 6 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 5f3a69f6ec34..0305485edcd3 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -379,3 +379,36 @@ void __init xen_add_extra_mem(unsigned long start_pfn, unsigned long n_pfns) memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns)); } + +#ifdef CONFIG_XEN_UNPOPULATED_ALLOC +int __init arch_xen_unpopulated_init(struct resource **res) +{ + unsigned int i; + + if (!xen_domain()) + return -ENODEV; + + /* Must be set strictly before calling xen_free_unpopulated_pages(). */ + *res = &iomem_resource; + + /* + * Initialize with pages from the extra memory regions (see + * arch/x86/xen/setup.c). + */ + for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { + unsigned int j; + + for (j = 0; j < xen_extra_mem[i].n_pfns; j++) { + struct page *pg = + pfn_to_page(xen_extra_mem[i].start_pfn + j); + + xen_free_unpopulated_pages(1, &pg); + } + + /* Zero so region is not also added to the balloon driver. */ + xen_extra_mem[i].n_pfns = 0; + } + + return 0; +} +#endif diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index 9bdc3b656b2c..99918beccd80 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -555,7 +555,6 @@ int xen_alloc_p2m_entry(unsigned long pfn) /* Separately check the mid mfn level */ unsigned long missing_mfn; unsigned long mid_mfn_mfn; - unsigned long old_mfn; mid_mfn = alloc_p2m_page(); if (!mid_mfn) @@ -565,12 +564,12 @@ int xen_alloc_p2m_entry(unsigned long pfn) missing_mfn = virt_to_mfn(p2m_mid_missing_mfn); mid_mfn_mfn = virt_to_mfn(mid_mfn); - old_mfn = cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn); - if (old_mfn != missing_mfn) { - free_p2m_page(mid_mfn); - mid_mfn = mfn_to_virt(old_mfn); - } else { + /* try_cmpxchg() updates missing_mfn on failure. */ + if (try_cmpxchg(top_mfn_p, &missing_mfn, mid_mfn_mfn)) { p2m_top_mfn_p[topidx] = mid_mfn; + } else { + free_p2m_page(mid_mfn); + mid_mfn = mfn_to_virt(missing_mfn); } } } else { |