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    Subject[tip: x86/cc] x86/sev: Replace occurrences of sev_es_active() with cc_platform_has()
    The following commit has been merged into the x86/cc branch of tip:

    Commit-ID: 6283f2effbd62a71a7c29062f8093c335ff3ea89
    Gitweb: https://git.kernel.org/tip/6283f2effbd62a71a7c29062f8093c335ff3ea89
    Author: Tom Lendacky <thomas.lendacky@amd.com>
    AuthorDate: Wed, 08 Sep 2021 17:58:38 -05:00
    Committer: Borislav Petkov <bp@suse.de>
    CommitterDate: Mon, 04 Oct 2021 11:47:09 +02:00

    x86/sev: Replace occurrences of sev_es_active() with cc_platform_has()

    Replace uses of sev_es_active() with the more generic cc_platform_has()
    using CC_ATTR_GUEST_STATE_ENCRYPT. If future support is added for other
    memory encyrption techonologies, the use of CC_ATTR_GUEST_STATE_ENCRYPT
    can be updated, as required.

    Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
    Signed-off-by: Borislav Petkov <bp@suse.de>
    Link: https://lkml.kernel.org/r/20210928191009.32551-8-bp@alien8.de
    ---
    arch/x86/include/asm/mem_encrypt.h | 2 --
    arch/x86/kernel/sev.c | 6 +++---
    arch/x86/mm/mem_encrypt.c | 24 +++---------------------
    arch/x86/realmode/init.c | 3 +--
    4 files changed, 7 insertions(+), 28 deletions(-)

    diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h
    index a5a58cc..da14ede 100644
    --- a/arch/x86/include/asm/mem_encrypt.h
    +++ b/arch/x86/include/asm/mem_encrypt.h
    @@ -51,7 +51,6 @@ void __init mem_encrypt_free_decrypted_mem(void);
    void __init mem_encrypt_init(void);

    void __init sev_es_init_vc_handling(void);
    -bool sev_es_active(void);

    #define __bss_decrypted __section(".bss..decrypted")

    @@ -74,7 +73,6 @@ static inline void __init sme_encrypt_kernel(struct boot_params *bp) { }
    static inline void __init sme_enable(struct boot_params *bp) { }

    static inline void sev_es_init_vc_handling(void) { }
    -static inline bool sev_es_active(void) { return false; }

    static inline int __init
    early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; }
    diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
    index a6895e4..53a6837 100644
    --- a/arch/x86/kernel/sev.c
    +++ b/arch/x86/kernel/sev.c
    @@ -11,7 +11,7 @@

    #include <linux/sched/debug.h> /* For show_regs() */
    #include <linux/percpu-defs.h>
    -#include <linux/mem_encrypt.h>
    +#include <linux/cc_platform.h>
    #include <linux/printk.h>
    #include <linux/mm_types.h>
    #include <linux/set_memory.h>
    @@ -615,7 +615,7 @@ int __init sev_es_efi_map_ghcbs(pgd_t *pgd)
    int cpu;
    u64 pfn;

    - if (!sev_es_active())
    + if (!cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
    return 0;

    pflags = _PAGE_NX | _PAGE_RW;
    @@ -774,7 +774,7 @@ void __init sev_es_init_vc_handling(void)

    BUILD_BUG_ON(offsetof(struct sev_es_runtime_data, ghcb_page) % PAGE_SIZE);

    - if (!sev_es_active())
    + if (!cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
    return;

    if (!sev_es_check_cpu_features())
    diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
    index 932007a..2d04c39 100644
    --- a/arch/x86/mm/mem_encrypt.c
    +++ b/arch/x86/mm/mem_encrypt.c
    @@ -361,25 +361,6 @@ int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size)
    return early_set_memory_enc_dec(vaddr, size, true);
    }

    -/*
    - * SME and SEV are very similar but they are not the same, so there are
    - * times that the kernel will need to distinguish between SME and SEV. The
    - * cc_platform_has() function is used for this. When a distinction isn't
    - * needed, the CC_ATTR_MEM_ENCRYPT attribute can be used.
    - *
    - * The trampoline code is a good example for this requirement. Before
    - * paging is activated, SME will access all memory as decrypted, but SEV
    - * will access all memory as encrypted. So, when APs are being brought
    - * up under SME the trampoline area cannot be encrypted, whereas under SEV
    - * the trampoline area must be encrypted.
    - */
    -
    -/* Needs to be called from non-instrumentable code */
    -bool noinstr sev_es_active(void)
    -{
    - return sev_status & MSR_AMD64_SEV_ES_ENABLED;
    -}
    -
    /* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
    bool force_dma_unencrypted(struct device *dev)
    {
    @@ -449,7 +430,7 @@ static void print_mem_encrypt_feature_info(void)
    pr_cont(" SEV");

    /* Encrypted Register State */
    - if (sev_es_active())
    + if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
    pr_cont(" SEV-ES");

    pr_cont("\n");
    @@ -468,7 +449,8 @@ void __init mem_encrypt_init(void)
    * With SEV, we need to unroll the rep string I/O instructions,
    * but SEV-ES supports them through the #VC handler.
    */
    - if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) && !sev_es_active())
    + if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) &&
    + !cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT))
    static_branch_enable(&sev_enable_key);

    print_mem_encrypt_feature_info();
    diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
    index c878c5e..4a3da75 100644
    --- a/arch/x86/realmode/init.c
    +++ b/arch/x86/realmode/init.c
    @@ -2,7 +2,6 @@
    #include <linux/io.h>
    #include <linux/slab.h>
    #include <linux/memblock.h>
    -#include <linux/mem_encrypt.h>
    #include <linux/cc_platform.h>
    #include <linux/pgtable.h>

    @@ -48,7 +47,7 @@ static void sme_sev_setup_real_mode(struct trampoline_header *th)
    if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
    th->flags |= TH_FLAGS_SME_ACTIVE;

    - if (sev_es_active()) {
    + if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) {
    /*
    * Skip the call to verify_cpu() in secondary_startup_64 as it
    * will cause #VC exceptions when the AP can't handle them yet.
    \
     
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