[Xen-changelog] [xen staging] x86/domain: don't destroy IOREQ servers on soft reset

[patchbot@xxxxxxx]

commit b376456a78ce893036002186d1003900a3b8833d
Author:     Igor Druzhinin <igor.druzhinin@xxxxxxxxxx>
AuthorDate: Fri Aug 30 15:23:01 2019 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Aug 30 15:23:01 2019 +0200

    x86/domain: don't destroy IOREQ servers on soft reset
    
    Performing soft reset should not opportunistically kill IOREQ servers
    for device emulators that might be currently running for a domain.
    Every emulator is supposed to clean up IOREQ servers for itself on exit.
    This allows a toolstack to elect whether or not a particular device
    model should be restarted.
    
    The original code was introduced in 3235cbfe ("arch-specific hooks for
    domain_soft_reset()") likely due to the fact 'default' IOREQ server
    existed in Xen at the time and used by QEMU didn't have an API call to
    destroy. Since the removal of 'default' IOREQ server from Xen this
    reason has gone away.
    
    Since commit ba7fdd64b ("xen: cleanup IOREQ server on exit") QEMU now
    destroys IOREQ server for itself as every other device emulator
    is supposed to do. It's now safe to remove this code from soft reset
    path - existing systems with old QEMU should be able to work as
    even if there are IOREQ servers left behind, a new QEMU instance will
    override its ranges anyway.
    
    Signed-off-by: Igor Druzhinin <igor.druzhinin@xxxxxxxxxx>
    Reviewed-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
    Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/arch/x86/domain.c         | 2 --
 xen/arch/x86/hvm/hvm.c        | 5 -----
 xen/include/asm-x86/hvm/hvm.h | 1 -
 3 files changed, 8 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 2df312332d..957f05937f 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -713,8 +713,6 @@ int arch_domain_soft_reset(struct domain *d)
     if ( !is_hvm_domain(d) )
         return -EINVAL;
 
-    hvm_domain_soft_reset(d);
-
     spin_lock(&d->event_lock);
     for ( i = 0; i < d->nr_pirqs ; i++ )
     {
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 029eea3b85..2b8189946b 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -5045,11 +5045,6 @@ void hvm_toggle_singlestep(struct vcpu *v)
     v->arch.hvm.single_step = !v->arch.hvm.single_step;
 }
 
-void hvm_domain_soft_reset(struct domain *d)
-{
-    hvm_destroy_all_ioreq_servers(d);
-}
-
 /*
  * Segment caches in VMCB/VMCS are inconsistent about which bits are checked,
  * important, and preserved across vmentry/exit.  Cook the values to make them
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index b327bd2524..4e72d0732e 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -240,7 +240,6 @@ extern const struct hvm_function_table *start_vmx(void);
 int hvm_domain_initialise(struct domain *d);
 void hvm_domain_relinquish_resources(struct domain *d);
 void hvm_domain_destroy(struct domain *d);
-void hvm_domain_soft_reset(struct domain *d);
 
 int hvm_vcpu_initialise(struct vcpu *v);
 void hvm_vcpu_destroy(struct vcpu *v);
--
generated by git-patchbot for /home/xen/git/xen.git#staging

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