Re: [PATCH V3 05/13] HV: Add Write/Read MSR registers via ghcb page

Subject: Re: [PATCH V3 05/13] HV: Add Write/Read MSR registers via ghcb page
From: Christoph Hellwig <hch@xxxxxx>
Date: Tue, 24 Aug 2021 10:45:27 +0200
Cc: kys@xxxxxxxxxxxxx, haiyangz@xxxxxxxxxxxxx, sthemmin@xxxxxxxxxxxxx, wei.liu@xxxxxxxxxx, decui@xxxxxxxxxxxxx, tglx@xxxxxxxxxxxxx, mingo@xxxxxxxxxx, bp@xxxxxxxxx, x86@xxxxxxxxxx, hpa@xxxxxxxxx, dave.hansen@xxxxxxxxxxxxxxx, luto@xxxxxxxxxx, peterz@xxxxxxxxxxxxx, konrad.wilk@xxxxxxxxxx, boris.ostrovsky@xxxxxxxxxx, jgross@xxxxxxxx, sstabellini@xxxxxxxxxx, joro@xxxxxxxxxx, will@xxxxxxxxxx, davem@xxxxxxxxxxxxx, kuba@xxxxxxxxxx, jejb@xxxxxxxxxxxxx, martin.petersen@xxxxxxxxxx, arnd@xxxxxxxx, hch@xxxxxx, m.szyprowski@xxxxxxxxxxx, robin.murphy@xxxxxxx, thomas.lendacky@xxxxxxx, brijesh.singh@xxxxxxx, ardb@xxxxxxxxxx, Tianyu.Lan@xxxxxxxxxxxxx, pgonda@xxxxxxxxxx, martin.b.radev@xxxxxxxxx, akpm@xxxxxxxxxxxxxxxxxxxx, kirill.shutemov@xxxxxxxxxxxxxxx, rppt@xxxxxxxxxx, sfr@xxxxxxxxxxxxxxxx, saravanand@xxxxxx, krish.sadhukhan@xxxxxxxxxx, aneesh.kumar@xxxxxxxxxxxxx, xen-devel@xxxxxxxxxxxxxxxxxxxx, rientjes@xxxxxxxxxx, hannes@xxxxxxxxxxx, tj@xxxxxxxxxx, michael.h.kelley@xxxxxxxxxxxxx, iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx, linux-arch@xxxxxxxxxxxxxxx, linux-hyperv@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, linux-scsi@xxxxxxxxxxxxxxx, netdev@xxxxxxxxxxxxxxx, vkuznets@xxxxxxxxxx, parri.andrea@xxxxxxxxx, dave.hansen@xxxxxxxxx
In-reply-to: <20210809175620.720923-6-ltykernel@gmail.com>
User-agent: Mutt/1.5.17 (2007-11-01)

This patch fails to compile when CONFIG_AMD_MEM_ENCRYPT is not enabled,
in which case there is sev_es_ghcb_hv_call_simple is not defined.

References:
- [PATCH V3 00/13] x86/Hyper-V: Add Hyper-V Isolation VM support
  - From: Tianyu Lan
- [PATCH V3 05/13] HV: Add Write/Read MSR registers via ghcb page
  - From: Tianyu Lan