From: Jing Liu Date: Wed, 5 Jan 2022 12:35:22 +0000 (-0800) Subject: x86/fpu: Prepare xfd_err in struct fpu_guest X-Git-Tag: baikal/aarch64/sdk6.1~4865^2~14 X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=4a2f7f29180ab55159cc72aed6b29bf866704694;p=kernel.git x86/fpu: Prepare xfd_err in struct fpu_guest When XFD causes an instruction to generate #NM, IA32_XFD_ERR contains information about which disabled state components are being accessed. The #NM handler is expected to check this information and then enable the state components by clearing IA32_XFD for the faulting task (if having permission). If the XFD_ERR value generated in guest is consumed/clobbered by the host before the guest itself doing so, it may lead to non-XFD-related #NM treated as XFD #NM in host (due to non-zero value in XFD_ERR), or XFD-related #NM treated as non-XFD #NM in guest (XFD_ERR cleared by the host #NM handler). Introduce a new field in fpu_guest to save the guest xfd_err value. KVM is expected to save guest xfd_err before interrupt is enabled and restore it right before entering the guest (with interrupt disabled). Signed-off-by: Jing Liu Signed-off-by: Kevin Tian Signed-off-by: Jing Liu Signed-off-by: Yang Zhong Message-Id: <20220105123532.12586-12-yang.zhong@intel.com> Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index c752d0aa23a46..3795d0573773e 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -517,6 +517,11 @@ struct fpu_guest { */ u64 perm; + /* + * @xfd_err: Save the guest value. + */ + u64 xfd_err; + /* * @fpstate: Pointer to the allocated guest fpstate */