From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Vrabel Subject: [PATCHv2 3/3] x86/hvm: add HVM_PARAM_X87_FIP_WIDTH Date: Tue, 23 Feb 2016 11:05:39 +0000 Message-ID: <1456225539-9162-4-git-send-email-david.vrabel@citrix.com> References: <1456225539-9162-1-git-send-email-david.vrabel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aYAms-00085r-W3 for xen-devel@lists.xenproject.org; Tue, 23 Feb 2016 11:05:51 +0000 In-Reply-To: <1456225539-9162-1-git-send-email-david.vrabel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xenproject.org Cc: Andrew Cooper , David Vrabel , Jan Beulich List-Id: xen-devel@lists.xenproject.org The HVM parameter HVM_PARAM_X87_FIP_WIDTH to allow tools and the guest to adjust the width of the FIP/FDP registers to be saved/restored by the hypervisor. This is in case the hypervisor hueristics do not do the right thing. Add this parameter to the set saved during domain save/migrate. Signed-off-by: David Vrabel --- tools/libxc/xc_sr_save_x86_hvm.c | 1 + xen/arch/x86/hvm/hvm.c | 13 +++++++++++++ xen/include/public/hvm/params.h | 24 +++++++++++++++++++++++- 3 files changed, 37 insertions(+), 1 deletion(-) diff --git a/tools/libxc/xc_sr_save_x86_hvm.c b/tools/libxc/xc_sr_save_x86_hvm.c index e347b3b..ba50a43 100644 --- a/tools/libxc/xc_sr_save_x86_hvm.c +++ b/tools/libxc/xc_sr_save_x86_hvm.c @@ -76,6 +76,7 @@ static int write_hvm_params(struct xc_sr_context *ctx) HVM_PARAM_VM_GENERATION_ID_ADDR, HVM_PARAM_IOREQ_SERVER_PFN, HVM_PARAM_NR_IOREQ_SERVER_PAGES, + HVM_PARAM_X87_FIP_WIDTH, }; xc_interface *xch = ctx->xch; diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index fe382ce..3583c9e 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -6027,6 +6027,7 @@ static int hvm_allow_set_param(struct domain *d, case HVM_PARAM_VM_GENERATION_ID_ADDR: case HVM_PARAM_STORE_EVTCHN: case HVM_PARAM_CONSOLE_EVTCHN: + case HVM_PARAM_X87_FIP_WIDTH: break; /* * The following parameters must not be set by the guest @@ -6222,6 +6223,14 @@ static int hvmop_set_param( break; } + case HVM_PARAM_X87_FIP_WIDTH: + if ( a.value != 0 && a.value != 4 && a.value != 8 ) + { + rc = -EINVAL; + break; + } + d->arch.x87_fip_width = a.value; + break; } if ( rc != 0 ) @@ -6258,6 +6267,7 @@ static int hvm_allow_get_param(struct domain *d, case HVM_PARAM_CONSOLE_PFN: case HVM_PARAM_CONSOLE_EVTCHN: case HVM_PARAM_ALTP2M: + case HVM_PARAM_X87_FIP_WIDTH: break; /* * The following parameters must not be read by the guest @@ -6307,6 +6317,9 @@ static int hvmop_get_param( case HVM_PARAM_ACPI_S_STATE: a.value = d->arch.hvm_domain.is_s3_suspended ? 3 : 0; break; + case HVM_PARAM_X87_FIP_WIDTH: + a.value = d->arch.x87_fip_width; + break; case HVM_PARAM_IOREQ_PFN: case HVM_PARAM_BUFIOREQ_PFN: case HVM_PARAM_BUFIOREQ_EVTCHN: diff --git a/xen/include/public/hvm/params.h b/xen/include/public/hvm/params.h index 81f9451..73d4718 100644 --- a/xen/include/public/hvm/params.h +++ b/xen/include/public/hvm/params.h @@ -210,6 +210,28 @@ /* Boolean: Enable altp2m */ #define HVM_PARAM_ALTP2M 35 -#define HVM_NR_PARAMS 36 +/* + * Size of the x87 FPU FIP/FDP registers that the hypervisor needs to + * save/restore. This is a workaround for a hardware limitation that + * does not allow the full FIP/FDP and FCS/FDS to be restored. + * + * Valid values are: + * + * 8: save/restore 64-bit FIP/FDP and clear FCS/FDS (default if CPU + * has FPCSDS feature). + * + * 4: save/restore 32-bit FIP/FDP, FCS/FDS, and clear upper 32-bits of + * FIP/FDP. + * + * 0: allow hypervisor to choose based on the value of FIP/FDP + * (default if CPU does not have FPCSDS). + * + * If FPCSDS (bit 13 in CPUID leaf 0x7, subleaf 0x0) is set, the CPU + * never saves FCS/FDS and this parameter should be left at the + * default of 8. + */ +#define HVM_PARAM_X87_FIP_WIDTH 36 + +#define HVM_NR_PARAMS 37 #endif /* __XEN_PUBLIC_HVM_PARAMS_H__ */ -- 2.1.4