9dd060afe2
This patch rolls back some of the changes introduced by commit
121f2faca2 "xen/balloon: rename alloc/free_xenballooned_pages"
in order to make possible to still allocate xenballooned pages
if CONFIG_XEN_UNPOPULATED_ALLOC is enabled.
On Arm the unpopulated pages will be allocated on top of extended
regions provided by Xen via device-tree (the subsequent patches
will add required bits to support unpopulated-alloc feature on Arm).
The problem is that extended regions feature has been introduced
into Xen quite recently (during 4.16 release cycle). So this
effectively means that Linux must only use unpopulated-alloc on Arm
if it is running on "new Xen" which advertises these regions.
But, it will only be known after parsing the "hypervisor" node
at boot time, so before doing that we cannot assume anything.
In order to keep working if CONFIG_XEN_UNPOPULATED_ALLOC is enabled
and the extended regions are not advertised (Linux is running on
"old Xen", etc) we need the fallback to alloc_xenballooned_pages().
This way we wouldn't reduce the amount of memory usable (wasting
RAM pages) for any of the external mappings anymore (and eliminate
XSA-300) with "new Xen", but would be still functional ballooning
out RAM pages with "old Xen".
Also rename alloc(free)_xenballooned_pages to xen_alloc(free)_ballooned_pages
and make xen_alloc(free)_unpopulated_pages static inline in xen.h
if CONFIG_XEN_UNPOPULATED_ALLOC is disabled.
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/1639080336-26573-4-git-send-email-olekstysh@gmail.com
Signed-off-by: Juergen Gross <jgross@suse.com>
73 lines
1.8 KiB
C
73 lines
1.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _XEN_XEN_H
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#define _XEN_XEN_H
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enum xen_domain_type {
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XEN_NATIVE, /* running on bare hardware */
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XEN_PV_DOMAIN, /* running in a PV domain */
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XEN_HVM_DOMAIN, /* running in a Xen hvm domain */
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};
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#ifdef CONFIG_XEN
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extern enum xen_domain_type xen_domain_type;
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#else
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#define xen_domain_type XEN_NATIVE
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#endif
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#ifdef CONFIG_XEN_PVH
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extern bool xen_pvh;
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#else
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#define xen_pvh 0
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#endif
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#define xen_domain() (xen_domain_type != XEN_NATIVE)
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#define xen_pv_domain() (xen_domain_type == XEN_PV_DOMAIN)
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#define xen_hvm_domain() (xen_domain_type == XEN_HVM_DOMAIN)
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#define xen_pvh_domain() (xen_pvh)
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#include <linux/types.h>
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extern uint32_t xen_start_flags;
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#include <xen/interface/hvm/start_info.h>
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extern struct hvm_start_info pvh_start_info;
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#ifdef CONFIG_XEN_DOM0
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#include <xen/interface/xen.h>
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#include <asm/xen/hypervisor.h>
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#define xen_initial_domain() (xen_domain() && \
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(xen_start_flags & SIF_INITDOMAIN))
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#else /* !CONFIG_XEN_DOM0 */
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#define xen_initial_domain() (0)
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#endif /* CONFIG_XEN_DOM0 */
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struct bio_vec;
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struct page;
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bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
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const struct page *page);
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#if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON)
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extern u64 xen_saved_max_mem_size;
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#endif
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#ifdef CONFIG_XEN_UNPOPULATED_ALLOC
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int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages);
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void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages);
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#else
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#include <xen/balloon.h>
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static inline int xen_alloc_unpopulated_pages(unsigned int nr_pages,
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struct page **pages)
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{
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return xen_alloc_ballooned_pages(nr_pages, pages);
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}
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static inline void xen_free_unpopulated_pages(unsigned int nr_pages,
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struct page **pages)
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{
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xen_free_ballooned_pages(nr_pages, pages);
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}
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#endif
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#endif /* _XEN_XEN_H */
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