Messages in this thread Patches in this message | | | Subject | Re: [RFC v2 28/32] x86/tdx: Make pages shared in ioremap() | From | "Kuppuswamy, Sathyanarayanan" <> | Date | Mon, 31 May 2021 10:32:44 -0700 |
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On 5/31/21 8:13 AM, Borislav Petkov wrote: > On Tue, May 25, 2021 at 11:21:21AM -0700, Kuppuswamy, Sathyanarayanan wrote: >> Following is the sample implementation. Please let me know your >> comments. > > Doesn't look like what I suggested here: > > https://lkml.kernel.org/r/YKfPLlulaqwypNkO@zn.tnic
IIUC, following are your design suggestions:
1. Define generic flags.
I think following flags are defined as you have suggested.
+++ b/include/linux/protected_guest.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _LINUX_PROTECTED_GUEST_H +#define _LINUX_PROTECTED_GUEST_H 1 + +/* Protected Guest Feature Flags (leave 0-0xff for arch specific flags) */ + +/* Support for guest encryption */ +#define VM_MEM_ENCRYPT 0x100 +/* Encryption support is active */ +#define VM_MEM_ENCRYPT_ACTIVE 0x101 +/* Support for unrolled string IO */ +#define VM_UNROLL_STRING_IO 0x102 +/* Support for host memory encryption */ +#define VM_HOST_MEM_ENCRYPT 0x103 2. Define generic functions and allow calls to arch specific implementations.
For above requirement, instead of calling arch specific functions from include/linux/protected_guest.h, I have directly included the arch specific file in linux/protected_guest.h
+#ifdef CONFIG_ARCH_HAS_PROTECTED_GUEST +#include <asm/protected_guest.h> +#else +static inline bool is_protected_guest(void) { return false; } +static inline bool protected_guest_has(unsigned long flag) { return false; } +#endif 3. Implement arch specific implementations respond to protected_guest_has() calls right?
I think above requirement is satisfied in following implementation.
+++ b/arch/x86/include/asm/protected_guest.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) 2020 Intel Corporation */ +#ifndef _ASM_PROTECTED_GUEST +#define _ASM_PROTECTED_GUEST 1 + +#include <asm/cpufeature.h> +#include <asm/tdx.h> + +/* Only include through linux/protected_guest.h */ + +static inline bool is_protected_guest(void) +{ + return boot_cpu_has(X86_FEATURE_TDX_GUEST); +} + +static inline bool protected_guest_has(unsigned long flag) +{ + if (boot_cpu_has(X86_FEATURE_TDX_GUEST)) + return tdx_protected_guest_has(flag); + + return false; +} + Did I misunderstand anything ? Please let me know your comments.
>
-- Sathyanarayanan Kuppuswamy Linux Kernel Developer
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