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Date:   Thu, 2 Jul 2020 18:21:52 +0000
From:   Anchal Agarwal <anchalag@amazon.com>
To:     <tglx@linutronix.de>, <mingo@redhat.com>, <bp@alien8.de>,
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Subject: [PATCH v2 03/11] x86/xen: Introduce new function to map
 HYPERVISOR_shared_info on Resume
Message-ID: <3601db44e7c543016ca67327393d9ae37019e408.1593665947.git.anchalag@amazon.com>
References: <cover.1593665947.git.anchalag@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.

Changelog:
v1->v2: Remove extra check for shared_info_pfn to be NULL

Signed-off-by: Anchal Agarwal <anchalag@amazon.com>
---
 arch/x86/xen/enlighten_hvm.c | 6 ++++++
 arch/x86/xen/xen-ops.h       | 1 +
 2 files changed, 7 insertions(+)

diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
index 3e89b0067ff0..d91099928746 100644
--- a/arch/x86/xen/enlighten_hvm.c
+++ b/arch/x86/xen/enlighten_hvm.c
@@ -28,6 +28,12 @@
 
 static unsigned long shared_info_pfn;
 
+void xen_hvm_map_shared_info(void)
+{
+	xen_hvm_init_shared_info();
+	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 53b224fd6177..41e9e9120f2d 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -54,6 +54,7 @@ void xen_enable_sysenter(void);
 void xen_enable_syscall(void);
 void xen_vcpu_restore(void);
 
+void xen_hvm_map_shared_info(void);
 void xen_hvm_init_shared_info(void);
 void xen_unplug_emulated_devices(void);
 
-- 
2.20.1