linux-stable/include/xen/xen-ops.h
Christoph Hellwig 566fb90e05 swiotlb-xen: fix DMA_ATTR_NO_KERNEL_MAPPING on arm
swiotlb-xen uses very different ways to allocate coherent memory on x86
vs arm.  On the former it allocates memory from the page allocator, while
on the later it reuses the dma-direct allocator the handles the
complexities of non-coherent DMA on arm platforms.

Unfortunately the complexities of trying to deal with the two cases in
the swiotlb-xen.c code lead to a bug in the handling of
DMA_ATTR_NO_KERNEL_MAPPING on arm.  With the DMA_ATTR_NO_KERNEL_MAPPING
flag the coherent memory allocator does not actually allocate coherent
memory, but just a DMA handle for some memory that is DMA addressable
by the device, but which does not have to have a kernel mapping.  Thus
dereferencing the return value will lead to kernel crashed and memory
corruption.

Fix this by using the dma-direct allocator directly for arm, which works
perfectly fine because on arm swiotlb-xen is only used when the domain is
1:1 mapped, and then simplifying the remaining code to only cater for the
x86 case with DMA coherent device.

Reported-by: Rahul Singh <Rahul.Singh@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Rahul Singh <rahul.singh@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Tested-by: Rahul Singh <rahul.singh@arm.com>
2022-05-11 19:48:32 +02:00

217 lines
6.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef INCLUDE_XEN_OPS_H
#define INCLUDE_XEN_OPS_H
#include <linux/percpu.h>
#include <linux/notifier.h>
#include <linux/efi.h>
#include <xen/features.h>
#include <asm/xen/interface.h>
#include <xen/interface/vcpu.h>
DECLARE_PER_CPU(struct vcpu_info *, xen_vcpu);
DECLARE_PER_CPU(uint32_t, xen_vcpu_id);
static inline uint32_t xen_vcpu_nr(int cpu)
{
return per_cpu(xen_vcpu_id, cpu);
}
#define XEN_VCPU_ID_INVALID U32_MAX
void xen_arch_pre_suspend(void);
void xen_arch_post_suspend(int suspend_cancelled);
void xen_timer_resume(void);
void xen_arch_resume(void);
void xen_arch_suspend(void);
void xen_reboot(int reason);
void xen_resume_notifier_register(struct notifier_block *nb);
void xen_resume_notifier_unregister(struct notifier_block *nb);
bool xen_vcpu_stolen(int vcpu);
void xen_setup_runstate_info(int cpu);
void xen_time_setup_guest(void);
void xen_manage_runstate_time(int action);
void xen_get_runstate_snapshot(struct vcpu_runstate_info *res);
u64 xen_steal_clock(int cpu);
int xen_setup_shutdown_event(void);
extern unsigned long *xen_contiguous_bitmap;
#if defined(CONFIG_XEN_PV)
int xen_remap_pfn(struct vm_area_struct *vma, unsigned long addr,
xen_pfn_t *pfn, int nr, int *err_ptr, pgprot_t prot,
unsigned int domid, bool no_translate);
#else
static inline int xen_remap_pfn(struct vm_area_struct *vma, unsigned long addr,
xen_pfn_t *pfn, int nr, int *err_ptr,
pgprot_t prot, unsigned int domid,
bool no_translate)
{
BUG();
return 0;
}
#endif
struct vm_area_struct;
#ifdef CONFIG_XEN_AUTO_XLATE
int xen_xlate_remap_gfn_array(struct vm_area_struct *vma,
unsigned long addr,
xen_pfn_t *gfn, int nr,
int *err_ptr, pgprot_t prot,
unsigned int domid,
struct page **pages);
int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma,
int nr, struct page **pages);
#else
/*
* These two functions are called from arch/x86/xen/mmu.c and so stubs
* are needed for a configuration not specifying CONFIG_XEN_AUTO_XLATE.
*/
static inline int xen_xlate_remap_gfn_array(struct vm_area_struct *vma,
unsigned long addr,
xen_pfn_t *gfn, int nr,
int *err_ptr, pgprot_t prot,
unsigned int domid,
struct page **pages)
{
return -EOPNOTSUPP;
}
static inline int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma,
int nr, struct page **pages)
{
return -EOPNOTSUPP;
}
#endif
int xen_remap_vma_range(struct vm_area_struct *vma, unsigned long addr,
unsigned long len);
/*
* xen_remap_domain_gfn_array() - map an array of foreign frames by gfn
* @vma: VMA to map the pages into
* @addr: Address at which to map the pages
* @gfn: Array of GFNs to map
* @nr: Number entries in the GFN array
* @err_ptr: Returns per-GFN error status.
* @prot: page protection mask
* @domid: Domain owning the pages
* @pages: Array of pages if this domain has an auto-translated physmap
*
* @gfn and @err_ptr may point to the same buffer, the GFNs will be
* overwritten by the error codes after they are mapped.
*
* Returns the number of successfully mapped frames, or a -ve error
* code.
*/
static inline int xen_remap_domain_gfn_array(struct vm_area_struct *vma,
unsigned long addr,
xen_pfn_t *gfn, int nr,
int *err_ptr, pgprot_t prot,
unsigned int domid,
struct page **pages)
{
if (xen_feature(XENFEAT_auto_translated_physmap))
return xen_xlate_remap_gfn_array(vma, addr, gfn, nr, err_ptr,
prot, domid, pages);
/* We BUG_ON because it's a programmer error to pass a NULL err_ptr,
* and the consequences later is quite hard to detect what the actual
* cause of "wrong memory was mapped in".
*/
BUG_ON(err_ptr == NULL);
return xen_remap_pfn(vma, addr, gfn, nr, err_ptr, prot, domid,
false);
}
/*
* xen_remap_domain_mfn_array() - map an array of foreign frames by mfn
* @vma: VMA to map the pages into
* @addr: Address at which to map the pages
* @mfn: Array of MFNs to map
* @nr: Number entries in the MFN array
* @err_ptr: Returns per-MFN error status.
* @prot: page protection mask
* @domid: Domain owning the pages
*
* @mfn and @err_ptr may point to the same buffer, the MFNs will be
* overwritten by the error codes after they are mapped.
*
* Returns the number of successfully mapped frames, or a -ve error
* code.
*/
static inline int xen_remap_domain_mfn_array(struct vm_area_struct *vma,
unsigned long addr, xen_pfn_t *mfn,
int nr, int *err_ptr,
pgprot_t prot, unsigned int domid)
{
if (xen_feature(XENFEAT_auto_translated_physmap))
return -EOPNOTSUPP;
return xen_remap_pfn(vma, addr, mfn, nr, err_ptr, prot, domid,
true);
}
/* xen_remap_domain_gfn_range() - map a range of foreign frames
* @vma: VMA to map the pages into
* @addr: Address at which to map the pages
* @gfn: First GFN to map.
* @nr: Number frames to map
* @prot: page protection mask
* @domid: Domain owning the pages
* @pages: Array of pages if this domain has an auto-translated physmap
*
* Returns the number of successfully mapped frames, or a -ve error
* code.
*/
static inline int xen_remap_domain_gfn_range(struct vm_area_struct *vma,
unsigned long addr,
xen_pfn_t gfn, int nr,
pgprot_t prot, unsigned int domid,
struct page **pages)
{
if (xen_feature(XENFEAT_auto_translated_physmap))
return -EOPNOTSUPP;
return xen_remap_pfn(vma, addr, &gfn, nr, NULL, prot, domid, false);
}
int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
int numpgs, struct page **pages);
int xen_xlate_map_ballooned_pages(xen_pfn_t **pfns, void **vaddr,
unsigned long nr_grant_frames);
bool xen_running_on_version_or_later(unsigned int major, unsigned int minor);
void xen_efi_runtime_setup(void);
#if defined(CONFIG_XEN_PV) && !defined(CONFIG_PREEMPTION)
DECLARE_PER_CPU(bool, xen_in_preemptible_hcall);
static inline void xen_preemptible_hcall_begin(void)
{
__this_cpu_write(xen_in_preemptible_hcall, true);
}
static inline void xen_preemptible_hcall_end(void)
{
__this_cpu_write(xen_in_preemptible_hcall, false);
}
#else
static inline void xen_preemptible_hcall_begin(void) { }
static inline void xen_preemptible_hcall_end(void) { }
#endif /* CONFIG_XEN_PV && !CONFIG_PREEMPTION */
#endif /* INCLUDE_XEN_OPS_H */