From: Julien Grall <julien.grall@arm.com>
Date: Mon, 28 Jan 2019 11:50:23 +0000 (+0000)
Subject: xen/arm: domain_build: Don't switch to the guest P2M when copying data
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=d0122fd7a406d5b9badaa2cb7c0479c3928db74e;p=people%2Fpauldu%2Fxen.git

xen/arm: domain_build: Don't switch to the guest P2M when copying data

Until recently, kernel/initrd/dtb were loaded using guest VA and
therefore requiring to restore temporarily the P2M. This was reworked
in a series of commits (up to 9292086 "xen/arm: domain_build: Use
copy_to_guest_phys_flush_dcache in dtb_load") to use a guest PA.

This will also help a follow-up patch which will require
p2m_{save,restore}_state to work in pair to workaround an erratum.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index d2c63a89ca..31af989e63 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -1923,7 +1923,6 @@ static void __init find_gnttab_region(struct domain *d,
 
 static int __init construct_domain(struct domain *d, struct kernel_info *kinfo)
 {
-    struct vcpu *saved_current;
     int i, cpu;
     struct vcpu *v = d->vcpu[0];
     struct cpu_user_regs *regs = &v->arch.cpu_info->guest_cpu_user_regs;
@@ -1944,14 +1943,6 @@ static int __init construct_domain(struct domain *d, struct kernel_info *kinfo)
 
 #endif
 
-    /*
-     * The following loads use the domain's p2m and require current to
-     * be a vcpu of the domain, temporarily switch
-     */
-    saved_current = current;
-    p2m_restore_state(v);
-    set_current(v);
-
     /*
      * kernel_load will determine the placement of the kernel as well
      * as the initrd & fdt in RAM, so call it first.
@@ -1961,10 +1952,6 @@ static int __init construct_domain(struct domain *d, struct kernel_info *kinfo)
     initrd_load(kinfo);
     dtb_load(kinfo);
 
-    /* Now that we are done restore the original p2m and current. */
-    set_current(saved_current);
-    p2m_restore_state(saved_current);
-
     memset(regs, 0, sizeof(*regs));
 
     regs->pc = (register_t)kinfo->entry;