[PATCH V9 2/9] x86/hyperv: Initialize shared memory boundary in the Isolation VM.

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, davem@davemloft.net,
	kuba@kernel.org, gregkh@linuxfoundation.org, arnd@arndb.de,
	brijesh.singh@amd.com, jroedel@suse.de, mikelley@microsoft.com,
	Tianyu.Lan@microsoft.com, thomas.lendacky@amd.com,
	pgonda@google.com, akpm@linux-foundation.org, rppt@kernel.org,
	kirill.shutemov@linux.intel.com, saravanand@fb.com,
	aneesh.kumar@linux.ibm.com, sfr@canb.auug.org.au,
	david@redhat.com, michael.h.kelley@microsoft.com
Cc: linux-arch@vger.kernel.org, linux-hyperv@vger.kernel.org,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	vkuznets@redhat.com, konrad.wilk@oracle.com, hch@lst.de,
	robin.murphy@arm.com, joro@8bytes.org, parri.andrea@gmail.com,
	dave.hansen@intel.com
Subject: [PATCH V9 2/9] x86/hyperv: Initialize shared memory boundary in the Isolation VM.
Date: Mon, 25 Oct 2021 08:21:07 -0400	[thread overview]
Message-ID: <20211025122116.264793-3-ltykernel@gmail.com> (raw)
In-Reply-To: <20211025122116.264793-1-ltykernel@gmail.com>

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.

Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
Change since v4:
	* Rename reserve field.

Change since v3:
	* user BIT_ULL to get shared_gpa_boundary
	* Rename field Reserved* to reserved
---
 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 b09ade389040..4794b716ec79 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -313,6 +313,8 @@ 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 =
+			BIT_ULL(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 2d88aa855f7e..a8ac497167d2 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -35,7 +35,17 @@ 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 reserved1 : 1;
+			u32 shared_gpa_boundary_active : 1;
+			u32 shared_gpa_boundary_bits : 6;
+			u32 reserved2 : 20;
+		};
+	};
+	u64 shared_gpa_boundary;
 };
 extern struct ms_hyperv_info ms_hyperv;
 
-- 
2.25.1

