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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,
	Tianyu.Lan@microsoft.com, rppt@kernel.org,
	kirill.shutemov@linux.intel.com, akpm@linux-foundation.org,
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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, parri.andrea@gmail.com
Subject: [PATCH V2 01/14] x86/HV: Initialize GHCB page in Isolation VM
Date: Wed,  4 Aug 2021 14:44:57 -0400	[thread overview]
Message-ID: <20210804184513.512888-2-ltykernel@gmail.com> (raw)
In-Reply-To: <20210804184513.512888-1-ltykernel@gmail.com>

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

Hyper-V exposes GHCB page via SEV ES GHCB MSR for SNP guest
to communicate with hypervisor. Map GHCB page for all
cpus to read/write MSR register and submit hvcall request
via GHCB.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 arch/x86/hyperv/hv_init.c       | 69 +++++++++++++++++++++++++++++++--
 arch/x86/include/asm/mshyperv.h |  2 +
 include/asm-generic/mshyperv.h  |  2 +
 3 files changed, 69 insertions(+), 4 deletions(-)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 4a643a85d570..247df301491f 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -20,6 +20,7 @@
 #include <linux/kexec.h>
 #include <linux/version.h>
 #include <linux/vmalloc.h>
+#include <linux/io.h>
 #include <linux/mm.h>
 #include <linux/hyperv.h>
 #include <linux/slab.h>
@@ -42,6 +43,31 @@ static void *hv_hypercall_pg_saved;
 struct hv_vp_assist_page **hv_vp_assist_page;
 EXPORT_SYMBOL_GPL(hv_vp_assist_page);
 
+static int hyperv_init_ghcb(void)
+{
+	u64 ghcb_gpa;
+	void *ghcb_va;
+	void **ghcb_base;
+
+	if (!ms_hyperv.ghcb_base)
+		return -EINVAL;
+
+	/*
+	 * GHCB page is allocated by paravisor. The address
+	 * returned by MSR_AMD64_SEV_ES_GHCB is above shared
+	 * ghcb boundary and map it here.
+	 */
+	rdmsrl(MSR_AMD64_SEV_ES_GHCB, ghcb_gpa);
+	ghcb_va = memremap(ghcb_gpa, HV_HYP_PAGE_SIZE, MEMREMAP_WB);
+	if (!ghcb_va)
+		return -ENOMEM;
+
+	ghcb_base = (void **)this_cpu_ptr(ms_hyperv.ghcb_base);
+	*ghcb_base = ghcb_va;
+
+	return 0;
+}
+
 static int hv_cpu_init(unsigned int cpu)
 {
 	struct hv_vp_assist_page **hvp = &hv_vp_assist_page[smp_processor_id()];
@@ -75,6 +101,8 @@ static int hv_cpu_init(unsigned int cpu)
 		wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, val);
 	}
 
+	hyperv_init_ghcb();
+
 	return 0;
 }
 
@@ -167,6 +195,14 @@ static int hv_cpu_die(unsigned int cpu)
 {
 	struct hv_reenlightenment_control re_ctrl;
 	unsigned int new_cpu;
+	void **ghcb_va = NULL;
+
+	if (ms_hyperv.ghcb_base) {
+		ghcb_va = (void **)this_cpu_ptr(ms_hyperv.ghcb_base);
+		if (*ghcb_va)
+			memunmap(*ghcb_va);
+		*ghcb_va = NULL;
+	}
 
 	hv_common_cpu_die(cpu);
 
@@ -340,9 +376,22 @@ void __init hyperv_init(void)
 			VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_ROX,
 			VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
 			__builtin_return_address(0));
-	if (hv_hypercall_pg == NULL) {
-		wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
-		goto remove_cpuhp_state;
+	if (hv_hypercall_pg == NULL)
+		goto clean_guest_os_id;
+
+	if (hv_isolation_type_snp()) {
+		ms_hyperv.ghcb_base = alloc_percpu(void *);
+		if (!ms_hyperv.ghcb_base)
+			goto clean_guest_os_id;
+
+		if (hyperv_init_ghcb()) {
+			free_percpu(ms_hyperv.ghcb_base);
+			ms_hyperv.ghcb_base = NULL;
+			goto clean_guest_os_id;
+		}
+
+		/* Hyper-V requires to write guest os id via ghcb in SNP IVM. */
+		hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, guest_id);
 	}
 
 	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
@@ -403,7 +452,8 @@ void __init hyperv_init(void)
 	hv_query_ext_cap(0);
 	return;
 
-remove_cpuhp_state:
+clean_guest_os_id:
+	wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
 	cpuhp_remove_state(cpuhp);
 free_vp_assist_page:
 	kfree(hv_vp_assist_page);
@@ -431,6 +481,9 @@ void hyperv_cleanup(void)
 	 */
 	hv_hypercall_pg = NULL;
 
+	if (ms_hyperv.ghcb_base)
+		free_percpu(ms_hyperv.ghcb_base);
+
 	/* Reset the hypercall page */
 	hypercall_msr.as_uint64 = 0;
 	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
@@ -506,3 +559,11 @@ bool hv_is_isolation_supported(void)
 {
 	return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
 }
+
+DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
+
+bool hv_isolation_type_snp(void)
+{
+	return static_branch_unlikely(&isolation_type_snp);
+}
+EXPORT_SYMBOL_GPL(hv_isolation_type_snp);
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index adccbc209169..6627cfd2bfba 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -11,6 +11,8 @@
 #include <asm/paravirt.h>
 #include <asm/mshyperv.h>
 
+DECLARE_STATIC_KEY_FALSE(isolation_type_snp);
+
 typedef int (*hyperv_fill_flush_list_func)(
 		struct hv_guest_mapping_flush_list *flush,
 		void *data);
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index c1ab6a6e72b5..4269f3174e58 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -36,6 +36,7 @@ struct ms_hyperv_info {
 	u32 max_lp_index;
 	u32 isolation_config_a;
 	u32 isolation_config_b;
+	void  __percpu **ghcb_base;
 };
 extern struct ms_hyperv_info ms_hyperv;
 
@@ -237,6 +238,7 @@ bool hv_is_hyperv_initialized(void);
 bool hv_is_hibernation_supported(void);
 enum hv_isolation_type hv_get_isolation_type(void);
 bool hv_is_isolation_supported(void);
+bool hv_isolation_type_snp(void);
 void hyperv_cleanup(void);
 bool hv_query_ext_cap(u64 cap_query);
 #else /* CONFIG_HYPERV */
-- 
2.25.1


  reply	other threads:[~2021-08-04 18:45 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-04 18:44 [PATCH V2 00/14] x86/Hyper-V: Add Hyper-V Isolation VM support Tianyu Lan
2021-08-04 18:44 ` Tianyu Lan [this message]
2021-08-04 18:44 ` [PATCH V2 02/14] x86/HV: Initialize shared memory boundary in the Isolation VM Tianyu Lan
2021-08-04 18:44 ` [PATCH V2 03/14] x86/set_memory: Add x86_set_memory_enc static call support Tianyu Lan
2021-08-04 19:27   ` Dave Hansen
2021-08-05 14:05     ` Tianyu Lan
2021-08-05 14:11       ` Peter Zijlstra
2021-08-05 14:23       ` Peter Zijlstra
2021-08-05 14:29         ` Dave Hansen
2021-08-05 15:51           ` Tianyu Lan
2021-08-04 18:45 ` [PATCH V2 04/14] x86/HV: Add new hvcall guest address host visibility support Tianyu Lan
2021-08-04 18:45 ` [PATCH V2 05/14] HV: Mark vmbus ring buffer visible to host in Isolation VM Tianyu Lan
2021-08-04 18:45 ` [PATCH V2 06/14] HV: Add Write/Read MSR registers via ghcb page Tianyu Lan
2021-08-04 18:45 ` [PATCH V2 07/14] HV: Add ghcb hvcall support for SNP VM Tianyu Lan
2021-08-04 18:45 ` [PATCH V2 08/14] HV/Vmbus: Add SNP support for VMbus channel initiate message Tianyu Lan
2021-08-04 18:45 ` [PATCH V2 09/14] HV/Vmbus: Initialize VMbus ring buffer for Isolation VM Tianyu Lan
2021-08-04 18:45 ` [PATCH V2 10/14] DMA: Add dma_map_decrypted/dma_unmap_encrypted() function Tianyu Lan
2021-08-05 15:56   ` Tianyu Lan
2021-08-04 18:45 ` [PATCH V2 11/14] x86/Swiotlb: Add Swiotlb bounce buffer remap function for HV IVM Tianyu Lan
2021-08-05 16:01   ` Tianyu Lan
2021-08-04 18:45 ` [PATCH V2 12/14] HV/IOMMU: Enable swiotlb bounce buffer for Isolation VM Tianyu Lan
2021-08-04 18:45 ` [PATCH V2 13/14] HV/Netvsc: Add Isolation VM support for netvsc driver Tianyu Lan
2021-08-04 18:45 ` [PATCH V2 14/14] HV/Storvsc: Add Isolation VM support for storvsc driver Tianyu Lan

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