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Date: Wed, 18 Dec 2013 14:27:08 +0000
From: Stefano Stabellini <stefano.stabellini@...citrix.com>
To: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
CC: <xen-devel@...ts.xenproject.org>, <linux-kernel@...r.kernel.org>,
<boris.ostrovsky@...cle.com>, <david.vrabel@...rix.com>,
<mukesh.rathor@...cle.com>, <jbeulich@...e.com>
Subject: Re: [Xen-devel] [PATCH v11 03/12] xen/pvh: Early bootup changes in
PV code.
On Tue, 17 Dec 2013, Konrad Rzeszutek Wilk wrote:
> From: Mukesh Rathor <mukesh.rathor@...cle.com>
>
> In the bootup code for PVH we can trap cpuid via vmexit, so don't
> need to use emulated prefix call. We also check for vector callback
> early on, as it is a required feature. PVH also runs at default kernel
> IOPL.
>
> Finally, pure PV settings are moved to a separate function that are
> only called for pure PV, ie, pv with pvmmu. They are also #ifdef
> with CONFIG_XEN_PVMMU.
>
> Signed-off-by: Mukesh Rathor <mukesh.rathor@...cle.com>
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
> ---
> arch/x86/xen/enlighten.c | 63 +++++++++++++++++++++++++++++++++---------------
> arch/x86/xen/setup.c | 18 +++++++++-----
> 2 files changed, 56 insertions(+), 25 deletions(-)
>
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index fa6ade7..3b21c82 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -46,6 +46,7 @@
> #include <xen/hvm.h>
> #include <xen/hvc-console.h>
> #include <xen/acpi.h>
> +#include <xen/features.h>
>
> #include <asm/paravirt.h>
> #include <asm/apic.h>
> @@ -262,8 +263,9 @@ static void __init xen_banner(void)
> struct xen_extraversion extra;
> HYPERVISOR_xen_version(XENVER_extraversion, &extra);
>
> - printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
> - pv_info.name);
> + pr_info("Booting paravirtualized kernel %son %s\n",
> + xen_feature(XENFEAT_auto_translated_physmap) ?
> + "with PVH extensions " : "", pv_info.name);
> printk(KERN_INFO "Xen version: %d.%d%s%s\n",
> version >> 16, version & 0xffff, extra.extraversion,
> xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
> @@ -331,12 +333,15 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
> break;
> }
>
> - asm(XEN_EMULATE_PREFIX "cpuid"
> - : "=a" (*ax),
> - "=b" (*bx),
> - "=c" (*cx),
> - "=d" (*dx)
> - : "0" (*ax), "2" (*cx));
> + if (xen_pvh_domain())
> + native_cpuid(ax, bx, cx, dx);
> + else
> + asm(XEN_EMULATE_PREFIX "cpuid"
> + : "=a" (*ax),
> + "=b" (*bx),
> + "=c" (*cx),
> + "=d" (*dx)
> + : "0" (*ax), "2" (*cx));
>
> *bx &= maskebx;
> *cx &= maskecx;
> @@ -1420,6 +1425,19 @@ static void __init xen_setup_stackprotector(void)
> pv_cpu_ops.load_gdt = xen_load_gdt;
> }
>
> +static void __init xen_pvh_early_guest_init(void)
> +{
> + if (xen_feature(XENFEAT_hvm_callback_vector))
> + xen_have_vector_callback = 1;
> +
> +#ifdef CONFIG_X86_32
> + if (xen_feature(XENFEAT_auto_translated_physmap)) {
> + xen_raw_printk("ERROR: 32bit PVH guests are not supported\n");
> + BUG();
> + }
> +#endif
Shouldn't we detect this error at build time?
If so, does it make sense to check for it at run time too?
The rest looks OK to me.
> +}
> +
> /* First C function to be called on Xen boot */
> asmlinkage void __init xen_start_kernel(void)
> {
> @@ -1431,13 +1449,18 @@ asmlinkage void __init xen_start_kernel(void)
>
> xen_domain_type = XEN_PV_DOMAIN;
>
> + xen_setup_features();
> + xen_pvh_early_guest_init();
> xen_setup_machphys_mapping();
>
> /* Install Xen paravirt ops */
> pv_info = xen_info;
> pv_init_ops = xen_init_ops;
> - pv_cpu_ops = xen_cpu_ops;
> pv_apic_ops = xen_apic_ops;
> + if (xen_pvh_domain())
> + pv_cpu_ops.cpuid = xen_cpuid;
> + else
> + pv_cpu_ops = xen_cpu_ops;
>
> x86_init.resources.memory_setup = xen_memory_setup;
> x86_init.oem.arch_setup = xen_arch_setup;
> @@ -1469,8 +1492,6 @@ asmlinkage void __init xen_start_kernel(void)
> /* Work out if we support NX */
> x86_configure_nx();
>
> - xen_setup_features();
> -
> /* Get mfn list */
> if (!xen_feature(XENFEAT_auto_translated_physmap))
> xen_build_dynamic_phys_to_machine();
> @@ -1548,14 +1569,18 @@ asmlinkage void __init xen_start_kernel(void)
> /* set the limit of our address space */
> xen_reserve_top();
>
> - /* We used to do this in xen_arch_setup, but that is too late on AMD
> - * were early_cpu_init (run before ->arch_setup()) calls early_amd_init
> - * which pokes 0xcf8 port.
> - */
> - set_iopl.iopl = 1;
> - rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
> - if (rc != 0)
> - xen_raw_printk("physdev_op failed %d\n", rc);
> + /* PVH: runs at default kernel iopl of 0 */
> + if (!xen_pvh_domain()) {
> + /*
> + * We used to do this in xen_arch_setup, but that is too late
> + * on AMD were early_cpu_init (run before ->arch_setup()) calls
> + * early_amd_init which pokes 0xcf8 port.
> + */
> + set_iopl.iopl = 1;
> + rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
> + if (rc != 0)
> + xen_raw_printk("physdev_op failed %d\n", rc);
> + }
>
> #ifdef CONFIG_X86_32
> /* set up basic CPUID stuff */
> diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
> index 68c054f..2137c51 100644
> --- a/arch/x86/xen/setup.c
> +++ b/arch/x86/xen/setup.c
> @@ -563,16 +563,13 @@ void xen_enable_nmi(void)
> BUG();
> #endif
> }
> -void __init xen_arch_setup(void)
> +void __init xen_pvmmu_arch_setup(void)
> {
> - xen_panic_handler_init();
> -
> HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
> HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
>
> - if (!xen_feature(XENFEAT_auto_translated_physmap))
> - HYPERVISOR_vm_assist(VMASST_CMD_enable,
> - VMASST_TYPE_pae_extended_cr3);
> + HYPERVISOR_vm_assist(VMASST_CMD_enable,
> + VMASST_TYPE_pae_extended_cr3);
>
> if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
> register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
> @@ -581,6 +578,15 @@ void __init xen_arch_setup(void)
> xen_enable_sysenter();
> xen_enable_syscall();
> xen_enable_nmi();
> +}
> +
> +/* This function is not called for HVM domains */
> +void __init xen_arch_setup(void)
> +{
> + xen_panic_handler_init();
> + if (!xen_feature(XENFEAT_auto_translated_physmap))
> + xen_pvmmu_arch_setup();
> +
> #ifdef CONFIG_ACPI
> if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
> printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
> --
> 1.8.3.1
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@...ts.xen.org
> http://lists.xen.org/xen-devel
>
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