Messages in this thread | | | Subject | Re: [RFC v2-fix-v2 1/1] x86: Introduce generic protected guest abstraction | From | "Kuppuswamy, Sathyanarayanan" <> | Date | Thu, 3 Jun 2021 11:33:53 -0700 |
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On 6/3/21 11:14 AM, Borislav Petkov wrote: > On Tue, Jun 01, 2021 at 02:14:17PM -0700, Kuppuswamy Sathyanarayanan wrote: >> diff --git a/include/linux/protected_guest.h b/include/linux/protected_guest.h >> new file mode 100644 >> index 000000000000..303dfba81d52 >> --- /dev/null >> +++ b/include/linux/protected_guest.h >> @@ -0,0 +1,40 @@ >> +/* SPDX-License-Identifier: GPL-2.0-only */ >> +#ifndef _LINUX_PROTECTED_GUEST_H >> +#define _LINUX_PROTECTED_GUEST_H 1 >> + >> +#include <linux/mem_encrypt.h> >> + >> +/* 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 >> +/* Support for shared mapping initialization (after early init) */ >> +#define VM_SHARED_MAPPING_INIT 0x104 > > Ok, a couple of things: > > first of all, those flags with that VM_ prefix make me think of > "virtual memory" instead of "virtual machine". So they should be > something else, like, say > > PR_G_... for Protected Guest or so. Or PR_GUEST or ...
I would prefer PR_GUEST over PR_G_
> > (yeah, good namespaces are all taken. ) > > Then, about the function name length, I'm fine if we did: > > prot_guest_has() > > or something even shorter, if you folks have a good suggestion. > > Anyway, below is a diff ontop of your tree with what I think the > barebones of this should be. > > As a reply to this message I went and converted sme_active() to use > protected_guest_has() too. > > Comments, complaints? > > Thx. > > --- > diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h > index 1492b0eb29d0..9c80c68d75b5 100644 > --- a/arch/x86/include/asm/mem_encrypt.h > +++ b/arch/x86/include/asm/mem_encrypt.h > @@ -56,8 +56,6 @@ bool sev_es_active(void); > > #define __bss_decrypted __section(".bss..decrypted") > > -bool amd_protected_guest_has(unsigned long flag); > - > #else /* !CONFIG_AMD_MEM_ENCRYPT */ > > #define sme_me_mask 0ULL > @@ -88,8 +86,6 @@ early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { return 0; > > static inline void mem_encrypt_free_decrypted_mem(void) { } > > -static inline bool amd_protected_guest_has(unsigned long flag) { return false; } > - > #define __bss_decrypted > > #endif /* CONFIG_AMD_MEM_ENCRYPT */ > diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h > index fa5cd05d3b5b..f09996c6a272 100644 > --- a/arch/x86/include/asm/sev.h > +++ b/arch/x86/include/asm/sev.h > @@ -11,6 +11,7 @@ > #include <linux/types.h> > #include <asm/insn.h> > #include <asm/sev-common.h> > +#include <asm/pgtable_types.h> > > #define GHCB_PROTO_OUR 0x0001UL > #define GHCB_PROTOCOL_MAX 1ULL > @@ -81,12 +82,15 @@ static __always_inline void sev_es_nmi_complete(void) > __sev_es_nmi_complete(); > } > extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd); > +bool sev_protected_guest_has(unsigned long flag); > + > #else > static inline void sev_es_ist_enter(struct pt_regs *regs) { } > static inline void sev_es_ist_exit(void) { } > static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; } > static inline void sev_es_nmi_complete(void) { } > static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; } > +static inline bool sev_protected_guest_has(unsigned long flag) { return false; } > #endif > > -#endif > +#endif /* __ASM_ENCRYPTED_STATE_H */ > diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c > index f7a743d122eb..01a224fdb897 100644 > --- a/arch/x86/kernel/sev.c > +++ b/arch/x86/kernel/sev.c > @@ -1402,3 +1402,14 @@ bool __init handle_vc_boot_ghcb(struct pt_regs *regs) > while (true) > halt(); > } > + > +bool sev_protected_guest_has(unsigned long flag) > +{ > + switch (flag) { > + case VM_MEM_ENCRYPT: > + case VM_MEM_ENCRYPT_ACTIVE: > + return true; > + } > + > + return false; > +}
I assume this file will get compiled for both SEV and SME cases.
> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c > index ced658e79753..49d11bb6e02a 100644 > --- a/arch/x86/mm/mem_encrypt.c > +++ b/arch/x86/mm/mem_encrypt.c > @@ -391,18 +391,6 @@ bool noinstr sev_es_active(void) > return sev_status & MSR_AMD64_SEV_ES_ENABLED; > } > > -bool amd_protected_guest_has(unsigned long flag) > -{ > - switch (flag) { > - case VM_MEM_ENCRYPT: > - case VM_MEM_ENCRYPT_ACTIVE: > - return true; > - } > - > - return false; > -} > -EXPORT_SYMBOL_GPL(amd_protected_guest_has); > - > /* Override for DMA direct allocation check - AMD specific initialization */ > bool amd_force_dma_unencrypted(struct device *dev) > { > diff --git a/include/linux/protected_guest.h b/include/linux/protected_guest.h > index 6855d5b3e244..bb4b1a06b21f 100644 > --- a/include/linux/protected_guest.h > +++ b/include/linux/protected_guest.h > @@ -2,7 +2,9 @@ > #ifndef _LINUX_PROTECTED_GUEST_H > #define _LINUX_PROTECTED_GUEST_H 1 > > -#include <linux/mem_encrypt.h> > +#include <asm/processor.h> > +#include <asm/tdx.h> > +#include <asm/sev.h> > > /* Protected Guest Feature Flags (leave 0-0xff for arch specific flags) */ > > @@ -20,23 +22,18 @@ > #define VM_DISABLE_UNCORE_SUPPORT 0x105 > > #if defined(CONFIG_INTEL_TDX_GUEST) || defined(CONFIG_AMD_MEM_ENCRYPT) > - > -#include <asm/tdx.h> > - > static inline bool protected_guest_has(unsigned long flag) > { > if (is_tdx_guest()) > return tdx_protected_guest_has(flag); > - else if (mem_encrypt_active()) > - return amd_protected_guest_has(flag); > + else if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) > + return sev_protected_guest_has(flag);
Since you are checking for AMD vendor ID, why not use amd_protected_guest_has()?
> > return false; > } > > #else > - > static inline bool protected_guest_has(unsigned long flag) { return false; } > - > #endif > > -#endif > +#endif /* _LINUX_PROTECTED_GUEST_H */ > >
-- Sathyanarayanan Kuppuswamy Linux Kernel Developer
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