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 --- include/asm-generic/video.h | 136 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) create mode 100644 include/asm-generic/video.h (limited to 'include/asm-generic/video.h') diff --git a/include/asm-generic/video.h b/include/asm-generic/video.h new file mode 100644 index 000000000..b1da2309d --- /dev/null +++ b/include/asm-generic/video.h @@ -0,0 +1,136 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __ASM_GENERIC_VIDEO_H_ +#define __ASM_GENERIC_VIDEO_H_ + +/* + * Only include this header file from your architecture's . + */ + +#include +#include +#include +#include + +struct device; + +#ifndef pgprot_framebuffer +#define pgprot_framebuffer pgprot_framebuffer +static inline pgprot_t pgprot_framebuffer(pgprot_t prot, + unsigned long vm_start, unsigned long vm_end, + unsigned long offset) +{ + return pgprot_writecombine(prot); +} +#endif + +#ifndef video_is_primary_device +#define video_is_primary_device video_is_primary_device +static inline bool video_is_primary_device(struct device *dev) +{ + return false; +} +#endif + +/* + * I/O helpers for the framebuffer. Prefer these functions over their + * regular counterparts. The regular I/O functions provide in-order + * access and swap bytes to/from little-endian ordering. Neither is + * required for framebuffers. Instead, the helpers read and write + * raw framebuffer data. Independent operations can be reordered for + * improved performance. + */ + +#ifndef fb_readb +static inline u8 fb_readb(const volatile void __iomem *addr) +{ + return __raw_readb(addr); +} +#define fb_readb fb_readb +#endif + +#ifndef fb_readw +static inline u16 fb_readw(const volatile void __iomem *addr) +{ + return __raw_readw(addr); +} +#define fb_readw fb_readw +#endif + +#ifndef fb_readl +static inline u32 fb_readl(const volatile void __iomem *addr) +{ + return __raw_readl(addr); +} +#define fb_readl fb_readl +#endif + +#ifndef fb_readq +#if defined(__raw_readq) +static inline u64 fb_readq(const volatile void __iomem *addr) +{ + return __raw_readq(addr); +} +#define fb_readq fb_readq +#endif +#endif + +#ifndef fb_writeb +static inline void fb_writeb(u8 b, volatile void __iomem *addr) +{ + __raw_writeb(b, addr); +} +#define fb_writeb fb_writeb +#endif + +#ifndef fb_writew +static inline void fb_writew(u16 b, volatile void __iomem *addr) +{ + __raw_writew(b, addr); +} +#define fb_writew fb_writew +#endif + +#ifndef fb_writel +static inline void fb_writel(u32 b, volatile void __iomem *addr) +{ + __raw_writel(b, addr); +} +#define fb_writel fb_writel +#endif + +#ifndef fb_writeq +#if defined(__raw_writeq) +static inline void fb_writeq(u64 b, volatile void __iomem *addr) +{ + __raw_writeq(b, addr); +} +#define fb_writeq fb_writeq +#endif +#endif + +#ifndef fb_memcpy_fromio +static inline void fb_memcpy_fromio(void *to, const volatile void __iomem *from, size_t n) +{ + memcpy_fromio(to, from, n); +} +#define fb_memcpy_fromio fb_memcpy_fromio +#endif + +#ifndef fb_memcpy_toio +static inline void fb_memcpy_toio(volatile void __iomem *to, const void *from, size_t n) +{ + memcpy_toio(to, from, n); +} +#define fb_memcpy_toio fb_memcpy_toio +#endif + +#ifndef fb_memset +static inline void fb_memset_io(volatile void __iomem *addr, int c, size_t n) +{ + memset_io(addr, c, n); +} +#define fb_memset fb_memset_io +#endif + +#endif /* __ASM_GENERIC_VIDEO_H_ */ -- cgit v1.3.1