Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
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, x86@kernel.org, hpa@zytor.com,
        dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org,
        konrad.wilk@oracle.com, boris.ostrovsky@oracle.com,
        jgross@suse.com, sstabellini@kernel.org, joro@8bytes.org,
        will@kernel.org, davem@davemloft.net, kuba@kernel.org,
        jejb@linux.ibm.com, martin.petersen@oracle.com, arnd@arndb.de,
        hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com,
        rppt@kernel.org, akpm@linux-foundation.org,
        kirill.shutemov@linux.intel.com, Tianyu.Lan@microsoft.com,
        thomas.lendacky@amd.com, ardb@kernel.org,
        nramas@linux.microsoft.com, robh@kernel.org, keescook@chromium.org,
        rientjes@google.com, pgonda@google.com, martin.b.radev@gmail.com,
        hannes@cmpxchg.org, saravanand@fb.com, krish.sadhukhan@oracle.com,
        xen-devel@lists.xenproject.org, tj@kernel.org,
        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, anparri@microsoft.com
Subject: [RFC PATCH V4 01/12] x86/HV: Initialize shared memory boundary in the Isolation VM.
Date:   Wed,  7 Jul 2021 11:34:42 -0400
Message-Id: <20210707153456.3976348-2-ltykernel@gmail.com>
In-Reply-To: <20210707153456.3976348-1-ltykernel@gmail.com>
References: <20210707153456.3976348-1-ltykernel@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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

Hyper-V exposes shared memory boundary via cpuid
HYPERV_CPUID_ISOLATION_CONFIG and store it in the
shared_gpa_boundary of ms_hyperv struct. This prepares
to share memory with host for SNP guest.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 arch/x86/kernel/cpu/mshyperv.c |  2 ++
 include/asm-generic/mshyperv.h | 12 +++++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 10b2a8c10cb6..8aed689db621 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -334,6 +334,8 @@ static void __init ms_hyperv_init_platform(void)
 	if (ms_hyperv.priv_high & HV_ISOLATION) {
 		ms_hyperv.isolation_config_a = cpuid_eax(HYPERV_CPUID_ISOLATION_CONFIG);
 		ms_hyperv.isolation_config_b = cpuid_ebx(HYPERV_CPUID_ISOLATION_CONFIG);
+		ms_hyperv.shared_gpa_boundary =
+			(u64)1 << ms_hyperv.shared_gpa_boundary_bits;
 
 		pr_info("Hyper-V: Isolation Config: Group A 0x%x, Group B 0x%x\n",
 			ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b);
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 3ae56a29594f..2914e27b0429 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -34,8 +34,18 @@ struct ms_hyperv_info {
 	u32 max_vp_index;
 	u32 max_lp_index;
 	u32 isolation_config_a;
-	u32 isolation_config_b;
+	union {
+		u32 isolation_config_b;
+		struct {
+			u32 cvm_type : 4;
+			u32 Reserved11 : 1;
+			u32 shared_gpa_boundary_active : 1;
+			u32 shared_gpa_boundary_bits : 6;
+			u32 Reserved12 : 20;
+		};
+	};
 	void  __percpu **ghcb_base;
+	u64 shared_gpa_boundary;
 };
 extern struct ms_hyperv_info ms_hyperv;
 
-- 
2.25.1