[PATCH v2 03/11] x86/xen: Introduce new function to map HYPERVISOR_shared_info on Resume

From: Anchal Agarwal
Date: Thu Jul 02 2020 - 14:22:39 EST


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@xxxxxxxxxx>
---
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