[ Upstream commit
3f6819dd192ef4f0c568ec3e9d6d408b3fa1ad3d ]
TDX code is going to provide guest.enc_status_change_prepare() that is
able to fail. TDX will use the call to convert the GPA range from shared
to private. This operation can fail.
Add a way to return an error from the callback.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://lore.kernel.org/all/20230606095622.1939-2-kirill.shutemov%40linux.intel.com
Stable-dep-of:
195edce08b63 ("x86/tdx: Fix race between set_memory_encrypted() and load_unaligned_zeropad()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
* @enc_cache_flush_required Returns true if a cache flush is needed before changing page encryption status
*/
struct x86_guest {
- void (*enc_status_change_prepare)(unsigned long vaddr, int npages, bool enc);
+ bool (*enc_status_change_prepare)(unsigned long vaddr, int npages, bool enc);
bool (*enc_status_change_finish)(unsigned long vaddr, int npages, bool enc);
bool (*enc_tlb_flush_required)(bool enc);
bool (*enc_cache_flush_required)(void);
static void default_nmi_init(void) { };
-static void enc_status_change_prepare_noop(unsigned long vaddr, int npages, bool enc) { }
+static bool enc_status_change_prepare_noop(unsigned long vaddr, int npages, bool enc) { return true; }
static bool enc_status_change_finish_noop(unsigned long vaddr, int npages, bool enc) { return false; }
static bool enc_tlb_flush_required_noop(bool enc) { return false; }
static bool enc_cache_flush_required_noop(void) { return false; }
#endif
}
-static void amd_enc_status_change_prepare(unsigned long vaddr, int npages, bool enc)
+static bool amd_enc_status_change_prepare(unsigned long vaddr, int npages, bool enc)
{
/*
* To maintain the security guarantees of SEV-SNP guests, make sure
*/
if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP) && !enc)
snp_set_memory_shared(vaddr, npages);
+
+ return true;
}
/* Return true unconditionally: return value doesn't matter for the SEV side */
cpa_flush(&cpa, x86_platform.guest.enc_cache_flush_required());
/* Notify hypervisor that we are about to set/clr encryption attribute. */
- x86_platform.guest.enc_status_change_prepare(addr, numpages, enc);
+ if (!x86_platform.guest.enc_status_change_prepare(addr, numpages, enc))
+ return -EIO;
ret = __change_page_attr_set_clr(&cpa, 1);