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authorLinus Torvalds <torvalds@linux-foundation.org>2024-05-24 19:24:49 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2024-05-24 19:24:49 +0200
commit9351f138d1dcbe504cd829abe590ba7f3387f09c (patch)
tree5b55a5ba42c0ba2d75c173452d7567c8093eb098 /arch/x86/xen
parentMerge tag 'for-6.10-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kda... (diff)
parentdrivers/xen: Improve the late XenStore init protocol (diff)
downloadlinux-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.c33
-rw-r--r--arch/x86/xen/p2m.c11
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 {