From:   Tianyu Lan <ltykernel@gmail.com>
To:     kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com,
        wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de,
        mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com,
        x86@kernel.org, hpa@zytor.com, davem@davemloft.net,
        kuba@kernel.org, jejb@linux.ibm.com, martin.petersen@oracle.com,
        arnd@arndb.de, hch@infradead.org, m.szyprowski@samsung.com,
        robin.murphy@arm.com, thomas.lendacky@amd.com,
        Tianyu.Lan@microsoft.com, michael.h.kelley@microsoft.com
Cc:     iommu@lists.linux-foundation.org, linux-arch@vger.kernel.org,
        linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-scsi@vger.kernel.org, netdev@vger.kernel.org,
        vkuznets@redhat.com, brijesh.singh@amd.com, konrad.wilk@oracle.com,
        hch@lst.de, joro@8bytes.org, parri.andrea@gmail.com,
        dave.hansen@intel.com
Subject: [PATCH V7 2/5] x86/hyper-v: Add hyperv Isolation VM check in the cc_platform_has()
Date:   Mon, 13 Dec 2021 02:14:03 -0500
Message-Id: <20211213071407.314309-3-ltykernel@gmail.com>
In-Reply-To: <20211213071407.314309-1-ltykernel@gmail.com>
References: <20211213071407.314309-1-ltykernel@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Tianyu Lan <Tianyu.Lan@microsoft.com>

Hyper-V provides Isolation VM for confidential computing support and
guest memory is encrypted in it. Places checking cc_platform_has()
with GUEST_MEM_ENCRYPT attr should return "True" in Isolation vm. e.g,
swiotlb bounce buffer size needs to adjust according to memory size
in the sev_setup_arch(). Add GUEST_MEM_ENCRYPT check for Hyper-V Isolation
VM.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
Change since v6:
	* Change the order in the cc_platform_has() and check sev first.

Change since v3:
	* Change code style of checking GUEST_MEM attribute in the
	  hyperv_cc_platform_has().
---
 arch/x86/kernel/cc_platform.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/x86/kernel/cc_platform.c b/arch/x86/kernel/cc_platform.c
index 03bb2f343ddb..6cb3a675e686 100644
--- a/arch/x86/kernel/cc_platform.c
+++ b/arch/x86/kernel/cc_platform.c
@@ -11,6 +11,7 @@
 #include <linux/cc_platform.h>
 #include <linux/mem_encrypt.h>
 
+#include <asm/mshyperv.h>
 #include <asm/processor.h>
 
 static bool __maybe_unused intel_cc_platform_has(enum cc_attr attr)
@@ -58,12 +59,19 @@ static bool amd_cc_platform_has(enum cc_attr attr)
 #endif
 }
 
+static bool hyperv_cc_platform_has(enum cc_attr attr)
+{
+	return attr == CC_ATTR_GUEST_MEM_ENCRYPT;
+}
 
 bool cc_platform_has(enum cc_attr attr)
 {
 	if (sme_me_mask)
 		return amd_cc_platform_has(attr);
 
+	if (hv_is_isolation_supported())
+		return hyperv_cc_platform_has(attr);
+
 	return false;
 }
 EXPORT_SYMBOL_GPL(cc_platform_has);
-- 
2.25.1