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    Subject[PATCHv9.1 06/17] x86/mm: Make x86_platform.guest.enc_status_change_*() return errno
    Date
    TDX is going to have more than one reason to fail
    enc_status_change_prepare().

    Change the callback to return errno instead of assuming -EIO;
    enc_status_change_finish() changed too to keep the interface symmetric.

    Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
    Reviewed-by: Dave Hansen <dave.hansen@intel.com>
    Reviewed-by: Kai Huang <kai.huang@intel.com>
    Tested-by: Tao Liu <ltao@redhat.com>
    ---
    v9.1:
    - Fix build error in Hyper-V code after rebase;
    ---
    arch/x86/coco/tdx/tdx.c | 20 +++++++++++---------
    arch/x86/hyperv/ivm.c | 22 ++++++++++------------
    arch/x86/include/asm/x86_init.h | 4 ++--
    arch/x86/kernel/x86_init.c | 4 ++--
    arch/x86/mm/mem_encrypt_amd.c | 8 ++++----
    arch/x86/mm/pat/set_memory.c | 8 +++++---
    6 files changed, 34 insertions(+), 32 deletions(-)

    diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
    index c1cb90369915..26fa47db5782 100644
    --- a/arch/x86/coco/tdx/tdx.c
    +++ b/arch/x86/coco/tdx/tdx.c
    @@ -798,28 +798,30 @@ static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc)
    return true;
    }

    -static bool tdx_enc_status_change_prepare(unsigned long vaddr, int numpages,
    - bool enc)
    +static int tdx_enc_status_change_prepare(unsigned long vaddr, int numpages,
    + bool enc)
    {
    /*
    * Only handle shared->private conversion here.
    * See the comment in tdx_early_init().
    */
    - if (enc)
    - return tdx_enc_status_changed(vaddr, numpages, enc);
    - return true;
    + if (enc && !tdx_enc_status_changed(vaddr, numpages, enc))
    + return -EIO;
    +
    + return 0;
    }

    -static bool tdx_enc_status_change_finish(unsigned long vaddr, int numpages,
    +static int tdx_enc_status_change_finish(unsigned long vaddr, int numpages,
    bool enc)
    {
    /*
    * Only handle private->shared conversion here.
    * See the comment in tdx_early_init().
    */
    - if (!enc)
    - return tdx_enc_status_changed(vaddr, numpages, enc);
    - return true;
    + if (!enc && !tdx_enc_status_changed(vaddr, numpages, enc))
    + return -EIO;
    +
    + return 0;
    }

    void __init tdx_early_init(void)
    diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
    index 768d73de0d09..b4a851d27c7c 100644
    --- a/arch/x86/hyperv/ivm.c
    +++ b/arch/x86/hyperv/ivm.c
    @@ -523,9 +523,9 @@ static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
    * transition is complete, hv_vtom_set_host_visibility() marks the pages
    * as "present" again.
    */
    -static bool hv_vtom_clear_present(unsigned long kbuffer, int pagecount, bool enc)
    +static int hv_vtom_clear_present(unsigned long kbuffer, int pagecount, bool enc)
    {
    - return !set_memory_np(kbuffer, pagecount);
    + return set_memory_np(kbuffer, pagecount);
    }

    /*
    @@ -536,20 +536,19 @@ static bool hv_vtom_clear_present(unsigned long kbuffer, int pagecount, bool enc
    * with host. This function works as wrap of hv_mark_gpa_visibility()
    * with memory base and size.
    */
    -static bool hv_vtom_set_host_visibility(unsigned long kbuffer, int pagecount, bool enc)
    +static int hv_vtom_set_host_visibility(unsigned long kbuffer, int pagecount, bool enc)
    {
    enum hv_mem_host_visibility visibility = enc ?
    VMBUS_PAGE_NOT_VISIBLE : VMBUS_PAGE_VISIBLE_READ_WRITE;
    u64 *pfn_array;
    phys_addr_t paddr;
    + int i, pfn, err;
    void *vaddr;
    int ret = 0;
    - bool result = true;
    - int i, pfn;

    pfn_array = kmalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
    if (!pfn_array) {
    - result = false;
    + ret = -ENOMEM;
    goto err_set_memory_p;
    }

    @@ -568,10 +567,8 @@ static bool hv_vtom_set_host_visibility(unsigned long kbuffer, int pagecount, bo
    if (pfn == HV_MAX_MODIFY_GPA_REP_COUNT || i == pagecount - 1) {
    ret = hv_mark_gpa_visibility(pfn, pfn_array,
    visibility);
    - if (ret) {
    - result = false;
    + if (ret)
    goto err_free_pfn_array;
    - }
    pfn = 0;
    }
    }
    @@ -586,10 +583,11 @@ static bool hv_vtom_set_host_visibility(unsigned long kbuffer, int pagecount, bo
    * order to avoid leaving the memory range in a "broken" state. Setting
    * the PRESENT bits shouldn't fail, but return an error if it does.
    */
    - if (set_memory_p(kbuffer, pagecount))
    - result = false;
    + err = set_memory_p(kbuffer, pagecount);
    + if (err && !ret)
    + ret = err;

    - return result;
    + return ret;
    }

    static bool hv_vtom_tlb_flush_required(bool private)
    diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
    index b89b40f250e6..4770af4d6015 100644
    --- a/arch/x86/include/asm/x86_init.h
    +++ b/arch/x86/include/asm/x86_init.h
    @@ -150,8 +150,8 @@ struct x86_init_acpi {
    * @enc_cache_flush_required Returns true if a cache flush is needed before changing page encryption status
    */
    struct x86_guest {
    - bool (*enc_status_change_prepare)(unsigned long vaddr, int npages, bool enc);
    - bool (*enc_status_change_finish)(unsigned long vaddr, int npages, bool enc);
    + int (*enc_status_change_prepare)(unsigned long vaddr, int npages, bool enc);
    + int (*enc_status_change_finish)(unsigned long vaddr, int npages, bool enc);
    bool (*enc_tlb_flush_required)(bool enc);
    bool (*enc_cache_flush_required)(void);
    };
    diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
    index a42830dc151b..69413ca37bfe 100644
    --- a/arch/x86/kernel/x86_init.c
    +++ b/arch/x86/kernel/x86_init.c
    @@ -132,8 +132,8 @@ struct x86_cpuinit_ops x86_cpuinit = {

    static void default_nmi_init(void) { };

    -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 true; }
    +static int enc_status_change_prepare_noop(unsigned long vaddr, int npages, bool enc) { return 0; }
    +static int enc_status_change_finish_noop(unsigned long vaddr, int npages, bool enc) { return 0; }
    static bool enc_tlb_flush_required_noop(bool enc) { return false; }
    static bool enc_cache_flush_required_noop(void) { return false; }
    static bool is_private_mmio_noop(u64 addr) {return false; }
    diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c
    index 70b91de2e053..d314e577836d 100644
    --- a/arch/x86/mm/mem_encrypt_amd.c
    +++ b/arch/x86/mm/mem_encrypt_amd.c
    @@ -283,7 +283,7 @@ static void enc_dec_hypercall(unsigned long vaddr, unsigned long size, bool enc)
    #endif
    }

    -static bool amd_enc_status_change_prepare(unsigned long vaddr, int npages, bool enc)
    +static int amd_enc_status_change_prepare(unsigned long vaddr, int npages, bool enc)
    {
    /*
    * To maintain the security guarantees of SEV-SNP guests, make sure
    @@ -292,11 +292,11 @@ static bool amd_enc_status_change_prepare(unsigned long vaddr, int npages, bool
    if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP) && !enc)
    snp_set_memory_shared(vaddr, npages);

    - return true;
    + return 0;
    }

    /* Return true unconditionally: return value doesn't matter for the SEV side */
    -static bool amd_enc_status_change_finish(unsigned long vaddr, int npages, bool enc)
    +static int amd_enc_status_change_finish(unsigned long vaddr, int npages, bool enc)
    {
    /*
    * After memory is mapped encrypted in the page table, validate it
    @@ -308,7 +308,7 @@ static bool amd_enc_status_change_finish(unsigned long vaddr, int npages, bool e
    if (!cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
    enc_dec_hypercall(vaddr, npages << PAGE_SHIFT, enc);

    - return true;
    + return 0;
    }

    static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
    diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
    index 80c9037ffadf..e5b454036bf3 100644
    --- a/arch/x86/mm/pat/set_memory.c
    +++ b/arch/x86/mm/pat/set_memory.c
    @@ -2156,7 +2156,8 @@ static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc)
    cpa_flush(&cpa, x86_platform.guest.enc_cache_flush_required());

    /* Notify hypervisor that we are about to set/clr encryption attribute. */
    - if (!x86_platform.guest.enc_status_change_prepare(addr, numpages, enc))
    + ret = x86_platform.guest.enc_status_change_prepare(addr, numpages, enc);
    + if (ret)
    goto vmm_fail;

    ret = __change_page_attr_set_clr(&cpa, 1);
    @@ -2174,7 +2175,8 @@ static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc)
    return ret;

    /* Notify hypervisor that we have successfully set/clr encryption attribute. */
    - if (!x86_platform.guest.enc_status_change_finish(addr, numpages, enc))
    + ret = x86_platform.guest.enc_status_change_finish(addr, numpages, enc);
    + if (ret)
    goto vmm_fail;

    return 0;
    @@ -2183,7 +2185,7 @@ static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc)
    WARN_ONCE(1, "CPA VMM failure to convert memory (addr=%p, numpages=%d) to %s.\n",
    (void *)addr, numpages, enc ? "private" : "shared");

    - return -EIO;
    + return ret;
    }

    static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
    --
    2.43.0

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