From 93de2a6a4b91b72607136dd656edf03fb399d27f Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 23 Sep 2026 09:37:21 -0700 Subject: KVM: SEV: Do cache maintenance on the source VM during intra-host migration Manually perform cache maintenance on the source VM during intra-host migration to ensure no stale data is left in CPU caches after the VM is destroyed. Because the source VM is "converted" to a non-SEV VM, KVM's memory reclaim flows won't trigger cache maintenance, e.g. when all guest memory is reclaimed in response to detaching from the mmu_notifier. Note, relying on the destination VM to do cache maintenance isn't an option as KVM doesn't require identical guest memory configurations, i.e. the source VM may have access to memory that the destination VM does not. Enforcing equivalent memory configurations is infeasible, as it would require a *deep* comparison of memslots, e.g. to verify that not only are the memslot identical, but what the memslots point at is also identical. Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration") Cc: stable@vger.kernel.org Reported-by: Stefan Teodorescu Signed-off-by: Sean Christopherson Message-ID: <20260923163721.1584779-3-seanjc@google.com> Signed-off-by: Paolo Bonzini --- drivers/video/fbdev/sbuslib.h | 63 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 drivers/video/fbdev/sbuslib.h (limited to 'drivers/video/fbdev/sbuslib.h') diff --git a/drivers/video/fbdev/sbuslib.h b/drivers/video/fbdev/sbuslib.h new file mode 100644 index 000000000..e9af2dc93 --- /dev/null +++ b/drivers/video/fbdev/sbuslib.h @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* sbuslib.h: SBUS fb helper library interfaces */ +#ifndef _SBUSLIB_H +#define _SBUSLIB_H + +struct device_node; +struct fb_info; +struct fb_var_screeninfo; +struct vm_area_struct; + +struct sbus_mmap_map { + unsigned long voff; + unsigned long poff; + unsigned long size; +}; + +#define SBUS_MMAP_FBSIZE(n) (-n) +#define SBUS_MMAP_EMPTY 0x80000000 + +extern void sbusfb_fill_var(struct fb_var_screeninfo *var, + struct device_node *dp, int bpp); +extern int sbusfb_mmap_helper(const struct sbus_mmap_map *map, + unsigned long physbase, unsigned long fbsize, + unsigned long iospace, + struct vm_area_struct *vma); +int sbusfb_ioctl_helper(unsigned long cmd, unsigned long arg, + struct fb_info *info, + int type, int fb_depth, unsigned long fb_size); +int sbusfb_compat_ioctl(struct fb_info *info, unsigned int cmd, + unsigned long arg); + +/* + * Initialize struct fb_ops for SBUS I/O. + */ + +#define __FB_DEFAULT_SBUS_OPS_RDWR(__prefix) \ + .fb_read = fb_io_read, \ + .fb_write = fb_io_write + +#define __FB_DEFAULT_SBUS_OPS_DRAW(__prefix) \ + .fb_fillrect = cfb_fillrect, \ + .fb_copyarea = cfb_copyarea, \ + .fb_imageblit = cfb_imageblit + +#ifdef CONFIG_COMPAT +#define __FB_DEFAULT_SBUS_OPS_IOCTL(__prefix) \ + .fb_ioctl = __prefix ## _sbusfb_ioctl, \ + .fb_compat_ioctl = sbusfb_compat_ioctl +#else +#define __FB_DEFAULT_SBUS_OPS_IOCTL(__prefix) \ + .fb_ioctl = __prefix ## _sbusfb_ioctl +#endif + +#define __FB_DEFAULT_SBUS_OPS_MMAP(__prefix) \ + .fb_mmap = __prefix ## _sbusfb_mmap + +#define FB_DEFAULT_SBUS_OPS(__prefix) \ + __FB_DEFAULT_SBUS_OPS_RDWR(__prefix), \ + __FB_DEFAULT_SBUS_OPS_DRAW(__prefix), \ + __FB_DEFAULT_SBUS_OPS_IOCTL(__prefix), \ + __FB_DEFAULT_SBUS_OPS_MMAP(__prefix) + +#endif /* _SBUSLIB_H */ -- cgit v1.3.1