[Xen-changelog] [xen-unstable] IA64: make the fpswa emulation keep the previous behaviour.

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
# Date 1229045758 -32400
# Node ID 05b293d7fbb7ef4505793410f370b951a6d8804c
# Parent  9e0f8f78d37a6c80339ed30b64099515211b5ebd
IA64: make the fpswa emulation keep the previous behaviour.

When fpswa library return statue > 0, keep the previous behavior.
This case should be addressed somehow later, but it seems somewhat
difficult to resolve, so keep the previous behavor for now.
It is assumed that a guest kernel calls fpswa library
without preemption. This assumption breaks if a guest kernel is
preemptive.

Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
---
 xen/arch/ia64/xen/faults.c    |    2 ++
 xen/arch/ia64/xen/hypercall.c |    7 +++++++
 xen/include/asm-ia64/domain.h |    1 +
 3 files changed, 10 insertions(+)

diff -r 9e0f8f78d37a -r 05b293d7fbb7 xen/arch/ia64/xen/faults.c
--- a/xen/arch/ia64/xen/faults.c        Fri Dec 12 10:34:18 2008 +0900
+++ b/xen/arch/ia64/xen/faults.c        Fri Dec 12 10:35:58 2008 +0900
@@ -337,6 +337,7 @@ handle_fpu_swa(int fp_fault, struct pt_r
                        rc = IA64_RETRY;
        }
        if (rc == IA64_RETRY) {
+               PSCBX(current, fpswa_ret) = (fpswa_ret_t){IA64_RETRY, 0, 0, 0};
                gdprintk(XENLOG_DEBUG,
                         "%s(%s): floating-point bundle at 0x%lx not mapped\n",
                         __FUNCTION__, fp_fault ? "fault" : "trap", fault_ip);
@@ -347,6 +348,7 @@ handle_fpu_swa(int fp_fault, struct pt_r
                         &isr, &regs->pr, &regs->cr_ifs, regs);
 
        if (ret.status) {
+               PSCBX(current, fpswa_ret) = ret;
                printk("%s(%s): fp_emulate() returned %ld\n",
                       __FUNCTION__, fp_fault ? "fault" : "trap", ret.status);
        }
diff -r 9e0f8f78d37a -r 05b293d7fbb7 xen/arch/ia64/xen/hypercall.c
--- a/xen/arch/ia64/xen/hypercall.c     Fri Dec 12 10:34:18 2008 +0900
+++ b/xen/arch/ia64/xen/hypercall.c     Fri Dec 12 10:35:58 2008 +0900
@@ -164,6 +164,13 @@ fw_hypercall_fpswa (struct vcpu *v, stru
        struct page_info *hp_page = NULL;
        struct page_info *hv_page = NULL;
        XEN_EFI_RR_DECLARE(rr6, rr7);
+
+       if (unlikely(PSCBX(v, fpswa_ret).status != 0 && 
+                    PSCBX(v, fpswa_ret).status != IA64_RETRY)) {
+               ret = PSCBX(v, fpswa_ret);
+               PSCBX(v, fpswa_ret) = (fpswa_ret_t){0, 0, 0, 0};
+               return ret;
+       }
 
        if (!fpswa_interface)
                goto error;
diff -r 9e0f8f78d37a -r 05b293d7fbb7 xen/include/asm-ia64/domain.h
--- a/xen/include/asm-ia64/domain.h     Fri Dec 12 10:34:18 2008 +0900
+++ b/xen/include/asm-ia64/domain.h     Fri Dec 12 10:35:58 2008 +0900
@@ -288,6 +288,7 @@ struct arch_vcpu {
     char irq_new_condition;    // vpsr.i/vtpr change, check for pending VHPI
     char hypercall_continuation;
 
+    fpswa_ret_t fpswa_ret;     /* save return values of FPSWA emulation */
     struct timer hlt_timer;
     struct arch_vmx_struct arch_vmx; /* Virtual Machine Extensions */
 

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