lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20210827172114.414281-2-ltykernel@gmail.com>
Date:   Fri, 27 Aug 2021 13:20:59 -0400
From:   Tianyu Lan <ltykernel@...il.com>
To:     kys@...rosoft.com, haiyangz@...rosoft.com, sthemmin@...rosoft.com,
        wei.liu@...nel.org, decui@...rosoft.com, catalin.marinas@....com,
        will@...nel.org, tglx@...utronix.de, mingo@...hat.com,
        bp@...en8.de, x86@...nel.org, hpa@...or.com,
        dave.hansen@...ux.intel.com, luto@...nel.org, peterz@...radead.org,
        konrad.wilk@...cle.com, boris.ostrovsky@...cle.com,
        jgross@...e.com, sstabellini@...nel.org, joro@...tes.org,
        davem@...emloft.net, kuba@...nel.org, jejb@...ux.ibm.com,
        martin.petersen@...cle.com, gregkh@...uxfoundation.org,
        arnd@...db.de, hch@....de, m.szyprowski@...sung.com,
        robin.murphy@....com, brijesh.singh@....com,
        thomas.lendacky@....com, Tianyu.Lan@...rosoft.com,
        pgonda@...gle.com, martin.b.radev@...il.com,
        akpm@...ux-foundation.org, kirill.shutemov@...ux.intel.com,
        rppt@...nel.org, hannes@...xchg.org, aneesh.kumar@...ux.ibm.com,
        krish.sadhukhan@...cle.com, saravanand@...com,
        linux-arm-kernel@...ts.infradead.org,
        xen-devel@...ts.xenproject.org, rientjes@...gle.com,
        ardb@...nel.org, michael.h.kelley@...rosoft.com
Cc:     iommu@...ts.linux-foundation.org, linux-arch@...r.kernel.org,
        linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-scsi@...r.kernel.org, netdev@...r.kernel.org,
        vkuznets@...hat.com, parri.andrea@...il.com, dave.hansen@...el.com
Subject: [PATCH V4 01/13] x86/hyperv: Initialize GHCB page in Isolation VM

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

Hyperv 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 page.

Signed-off-by: Tianyu Lan <Tianyu.Lan@...rosoft.com>
---
Chagne since v3:
        * Rename ghcb_base to hv_ghcb_pg and move it out of
	  struct ms_hyperv_info.
	* Allocate hv_ghcb_pg before cpuhp_setup_state() and leverage
	  hv_cpu_init() to initialize ghcb page.
---
 arch/x86/hyperv/hv_init.c       | 68 +++++++++++++++++++++++++++++----
 arch/x86/include/asm/mshyperv.h |  4 ++
 arch/x86/kernel/cpu/mshyperv.c  |  3 ++
 include/asm-generic/mshyperv.h  |  1 +
 4 files changed, 69 insertions(+), 7 deletions(-)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 708a2712a516..eba10ed4f73e 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>
@@ -36,12 +37,42 @@ EXPORT_SYMBOL_GPL(hv_current_partition_id);
 void *hv_hypercall_pg;
 EXPORT_SYMBOL_GPL(hv_hypercall_pg);
 
+void __percpu **hv_ghcb_pg;
+
 /* Storage to save the hypercall page temporarily for hibernation */
 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 (!hv_isolation_type_snp())
+		return 0;
+
+	if (!hv_ghcb_pg)
+		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(hv_ghcb_pg);
+	*ghcb_base = ghcb_va;
+
+	return 0;
+}
+
 static int hv_cpu_init(unsigned int cpu)
 {
 	union hv_vp_assist_msr_contents msr = { 0 };
@@ -85,7 +116,7 @@ static int hv_cpu_init(unsigned int cpu)
 		}
 	}
 
-	return 0;
+	return hyperv_init_ghcb();
 }
 
 static void (*hv_reenlightenment_cb)(void);
@@ -177,6 +208,14 @@ static int hv_cpu_die(unsigned int cpu)
 {
 	struct hv_reenlightenment_control re_ctrl;
 	unsigned int new_cpu;
+	void **ghcb_va;
+
+	if (hv_ghcb_pg) {
+		ghcb_va = (void **)this_cpu_ptr(hv_ghcb_pg);
+		if (*ghcb_va)
+			memunmap(*ghcb_va);
+		*ghcb_va = NULL;
+	}
 
 	hv_common_cpu_die(cpu);
 
@@ -366,10 +405,16 @@ void __init hyperv_init(void)
 		goto common_free;
 	}
 
+	if (hv_isolation_type_snp()) {
+		hv_ghcb_pg = alloc_percpu(void *);
+		if (!hv_ghcb_pg)
+			goto free_vp_assist_page;
+	}
+
 	cpuhp = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/hyperv_init:online",
 				  hv_cpu_init, hv_cpu_die);
 	if (cpuhp < 0)
-		goto free_vp_assist_page;
+		goto free_ghcb_page;
 
 	/*
 	 * Setup the hypercall page and enable hypercalls.
@@ -383,10 +428,8 @@ 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;
 
 	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 	hypercall_msr.enable = 1;
@@ -456,8 +499,11 @@ 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_ghcb_page:
+	free_percpu(hv_ghcb_pg);
 free_vp_assist_page:
 	kfree(hv_vp_assist_page);
 	hv_vp_assist_page = NULL;
@@ -559,3 +605,11 @@ 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..37739a277ac6 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);
@@ -39,6 +41,8 @@ extern void *hv_hypercall_pg;
 
 extern u64 hv_current_partition_id;
 
+extern void __percpu **hv_ghcb_pg;
+
 int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages);
 int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id);
 int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags);
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 6b5835a087a3..20557a9d6e25 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -316,6 +316,9 @@ static void __init ms_hyperv_init_platform(void)
 
 		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);
+
+		if (hv_get_isolation_type() == HV_ISOLATION_TYPE_SNP)
+			static_branch_enable(&isolation_type_snp);
 	}
 
 	if (hv_max_functions_eax >= HYPERV_CPUID_NESTED_FEATURES) {
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index c1ab6a6e72b5..0924bbd8458e 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -237,6 +237,7 @@ 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

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ