From: Tianyu Lan <ltykernel@xxxxxxxxx> Sent: Monday, August 9, 2021 10:56 AM
[snip]
> diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
> index ad8a5c586a35..1e4a0882820a 100644
> --- a/arch/x86/mm/pat/set_memory.c
> +++ b/arch/x86/mm/pat/set_memory.c
> @@ -29,6 +29,8 @@
> #include <asm/proto.h>
> #include <asm/memtype.h>
> #include <asm/set_memory.h>
> +#include <asm/hyperv-tlfs.h>
> +#include <asm/mshyperv.h>
>
> #include "../mm_internal.h"
>
> @@ -1980,15 +1982,11 @@ int set_memory_global(unsigned long addr, int numpages)
> __pgprot(_PAGE_GLOBAL), 0);
> }
>
> -static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
> +static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc)
> {
> struct cpa_data cpa;
> int ret;
>
> - /* Nothing to do if memory encryption is not active */
> - if (!mem_encrypt_active())
> - return 0;
> -
> /* Should not be working on unaligned addresses */
> if (WARN_ONCE(addr & ~PAGE_MASK, "misaligned address: %#lx\n", addr))
> addr &= PAGE_MASK;
> @@ -2023,6 +2021,17 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
> return ret;
> }
>
> +static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
> +{
> + if (hv_is_isolation_supported())
> + return hv_set_mem_host_visibility(addr, numpages, !enc);
> +
> + if (mem_encrypt_active())
> + return __set_memory_enc_pgtable(addr, numpages, enc);
> +
> + return 0;
> +}
> +
FYI, this not-yet-accepted patch
https://lore.kernel.org/lkml/ab5a7a983a943e7ca0a7ad28275a2d094c62c371.1623421410.git.ashish.kalra@xxxxxxx/
looks to be providing a generic hook to notify the hypervisor when the
encryption status of a memory range changes.
Michael
