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Date:   Wed, 12 Feb 2020 22:31:34 +0000
From:   Anchal Agarwal <anchalag@amazon.com>
To:     <tglx@linutronix.de>, <mingo@redhat.com>, <bp@alien8.de>,
        <hpa@zytor.com>, <x86@kernel.org>, <boris.ostrovsky@oracle.com>,
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        <anchalag@amazon.com>, <xen-devel@lists.xenproject.org>,
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        <fllinden@amaozn.com>, <benh@kernel.crashing.org>
Subject: [RFC PATCH v3 03/12] x86/xen: Introduce new function to map
 HYPERVISOR_shared_info on Resume
Message-ID: <20200212223134.GA3625@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com>
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Introduce a small function which re-uses shared page's PA allocated
during guest initialization time in reserve_shared_info() and not
allocate new page during resume flow.
It also  does the mapping of shared_info_page by calling
xen_hvm_init_shared_info() to use the function.

Signed-off-by: Anchal Agarwal <anchalag@amazon.com>

---
Changes since V2: None
---
 arch/x86/xen/enlighten_hvm.c | 7 +++++++
 arch/x86/xen/xen-ops.h       | 1 +
 2 files changed, 8 insertions(+)

diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
index e138f7de52d2..75b1ec7a0fcd 100644
--- a/arch/x86/xen/enlighten_hvm.c
+++ b/arch/x86/xen/enlighten_hvm.c
@@ -27,6 +27,13 @@
 
 static unsigned long shared_info_pfn;
 
+void xen_hvm_map_shared_info(void)
+{
+	xen_hvm_init_shared_info();
+	if (shared_info_pfn)
+		HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn));
+}
+
 void xen_hvm_init_shared_info(void)
 {
 	struct xen_add_to_physmap xatp;
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 45a441c33d6d..d84c357994bd 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -56,6 +56,7 @@ void xen_enable_syscall(void);
 void xen_vcpu_restore(void);
 
 void xen_callback_vector(void);
+void xen_hvm_map_shared_info(void);
 void xen_hvm_init_shared_info(void);
 void xen_unplug_emulated_devices(void);
 
-- 
2.24.1.AMZN