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2020-06-11x86/entry: Convert XEN hypercall vector to IDTENTRY_SYSVECThomas Gleixner
Convert the last oldstyle defined vector to IDTENTRY_SYSVEC: - Implement the C entry point with DEFINE_IDTENTRY_SYSVEC - Emit the ASM stub with DECLARE_IDTENTRY_SYSVEC - Remove the ASM idtentries in 64-bit - Remove the BUILD_INTERRUPT entries in 32-bit - Remove the old prototypes Fixup the related XEN code by providing the primary C entry point in x86 to avoid cluttering the generic code with X86'isms. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20200521202119.741950104@linutronix.de
2019-07-17x86/xen: Add "nopv" support for HVM guestZhenzhong Duan
PVH guest needs PV extentions to work, so "nopv" parameter should be ignored for PVH but not for HVM guest. If PVH guest boots up via the Xen-PVH boot entry, xen_pvh is set early, we know it's PVH guest and ignore "nopv" parameter directly. If PVH guest boots up via the normal boot entry same as HVM guest, it's hard to distinguish PVH and HVM guest at that time. In this case, we have to panic early if PVH is detected and nopv is enabled to avoid a worse situation later. Remove static from bool_x86_init_noop/x86_op_int_noop so they could be used globally. Move xen_platform_hvm() after xen_hvm_guest_late_init() to avoid compile error. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-07-17x86/paravirt: Remove const mark from x86_hyper_xen_hvm variableZhenzhong Duan
.. as "nopv" support needs it to be changeable at boot up stage. Checkpatch reports warning, so move variable declarations from hypervisor.c to hypervisor.h Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-07-17xen: Map "xen_nopv" parameter to "nopv" and mark it obsoleteZhenzhong Duan
Clean up unnecessory code after that operation. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Signed-off-by: Juergen Gross <jgross@suse.com>
2019-07-17x86/xen: Mark xen_hvm_need_lapic() and xen_x2apic_para_available() as __initZhenzhong Duan
.. as they are only called at early bootup stage. In fact, other functions in x86_hyper_xen_hvm.init.* are all marked as __init. Unexport xen_hvm_need_lapic as it's never used outside. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Signed-off-by: Juergen Gross <jgross@suse.com>
2018-09-03x86/xen: Add SPDX identifier in arch/x86/xen filesJuergen Gross
Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: xen-devel@lists.xenproject.org Cc: virtualization@lists.linux-foundation.org Cc: akataria@vmware.com Cc: rusty@rustcorp.com.au Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/20180828074026.820-5-jgross@suse.com
2018-05-07x86/xen: Reset VCPU0 info pointer after shared_info remapvan der Linden, Frank
This patch fixes crashes during boot for HVM guests on older (pre HVM vector callback) Xen versions. Without this, current kernels will always fail to boot on those Xen versions. Sample stack trace: BUG: unable to handle kernel paging request at ffffffffff200000 IP: __xen_evtchn_do_upcall+0x1e/0x80 PGD 1e0e067 P4D 1e0e067 PUD 1e10067 PMD 235c067 PTE 0 Oops: 0002 [#1] SMP PTI Modules linked in: CPU: 0 PID: 512 Comm: kworker/u2:0 Not tainted 4.14.33-52.13.amzn1.x86_64 #1 Hardware name: Xen HVM domU, BIOS 3.4.3.amazon 11/11/2016 task: ffff88002531d700 task.stack: ffffc90000480000 RIP: 0010:__xen_evtchn_do_upcall+0x1e/0x80 RSP: 0000:ffff880025403ef0 EFLAGS: 00010046 RAX: ffffffff813cc760 RBX: ffffffffff200000 RCX: ffffc90000483ef0 RDX: ffff880020540a00 RSI: ffff880023c78000 RDI: 000000000000001c RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff880025403f5c R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff880025400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff200000 CR3: 0000000001e0a000 CR4: 00000000000006f0 Call Trace: <IRQ> do_hvm_evtchn_intr+0xa/0x10 __handle_irq_event_percpu+0x43/0x1a0 handle_irq_event_percpu+0x20/0x50 handle_irq_event+0x39/0x60 handle_fasteoi_irq+0x80/0x140 handle_irq+0xaf/0x120 do_IRQ+0x41/0xd0 common_interrupt+0x7d/0x7d </IRQ> During boot, the HYPERVISOR_shared_info page gets remapped to make it work with KASLR. This means that any pointer derived from it needs to be adjusted. The only value that this applies to is the vcpu_info pointer for VCPU 0. For PV and HVM with the callback vector feature, this gets done via the smp_ops prepare_boot_cpu callback. Older Xen versions do not support the HVM callback vector, so there is no Xen-specific smp_ops set up in that scenario. So, the vcpu_info pointer for VCPU 0 never gets set to the proper value, and the first reference of it will be bad. Fix this by resetting it immediately after the remap. Signed-off-by: Frank van der Linden <fllinden@amazon.com> Reviewed-by: Eduardo Valentin <eduval@amazon.com> Reviewed-by: Alakesh Haloi <alakeshh@amazon.com> Reviewed-by: Vallish Vaidyeshwara <vallish@amazon.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: xen-devel@lists.xenproject.org Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-11-10x86/virt/xen: Use guest_late_init to detect Xen PVH guestJuergen Gross
In case we are booted via the default boot entry by a generic loader like grub or OVMF it is necessary to distinguish between a HVM guest with a device model supporting legacy devices and a PVH guest without device model. PVH guests will always have x86_platform.legacy.no_vga set and x86_platform.legacy.rtc cleared, while both won't be true for HVM guests. Test for both conditions in the guest_late_init hook and set xen_pvh to true if they are met. Move some of the early PVH initializations to the new hook in order to avoid duplicated code. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: boris.ostrovsky@oracle.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20171109132739.23465-6-jgross@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-10x86/virt: Add enum for hypervisors to replace x86_hyperJuergen Gross
The x86_hyper pointer is only used for checking whether a virtual device is supporting the hypervisor the system is running on. Use an enum for that purpose instead and drop the x86_hyper pointer. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Xavier Deguillard <xdeguillard@vmware.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: akataria@vmware.com Cc: arnd@arndb.de Cc: boris.ostrovsky@oracle.com Cc: devel@linuxdriverproject.org Cc: dmitry.torokhov@gmail.com Cc: gregkh@linuxfoundation.org Cc: haiyangz@microsoft.com Cc: kvm@vger.kernel.org Cc: kys@microsoft.com Cc: linux-graphics-maintainer@vmware.com Cc: linux-input@vger.kernel.org Cc: moltmann@vmware.com Cc: pbonzini@redhat.com Cc: pv-drivers@vmware.com Cc: rkrcmar@redhat.com Cc: sthemmin@microsoft.com Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20171109132739.23465-3-jgross@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-10x86/virt, x86/platform: Merge 'struct x86_hyper' into 'struct x86_platform' ↵Juergen Gross
and 'struct x86_init' Instead of x86_hyper being either NULL on bare metal or a pointer to a struct hypervisor_x86 in case of the kernel running as a guest merge the struct into x86_platform and x86_init. This will remove the need for wrappers making it hard to find out what is being called. With dummy functions added for all callbacks testing for a NULL function pointer can be removed, too. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: akataria@vmware.com Cc: boris.ostrovsky@oracle.com Cc: devel@linuxdriverproject.org Cc: haiyangz@microsoft.com Cc: kvm@vger.kernel.org Cc: kys@microsoft.com Cc: pbonzini@redhat.com Cc: rkrcmar@redhat.com Cc: rusty@rustcorp.com.au Cc: sthemmin@microsoft.com Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20171109132739.23465-2-jgross@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-11xen: fix hvm guest with kaslr enabledJuergen Gross
A Xen HVM guest running with KASLR enabled will die rather soon today because the shared info page mapping is using va() too early. This was introduced by commit a5d5f328b0e2baa5ee7c119fd66324eb79eeeb66 ("xen: allocate page for shared info page from low memory"). In order to fix this use early_memremap() to get a temporary virtual address for shared info until va() can be used safely. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-08-11xen: split up xen_hvm_init_shared_info()Juergen Gross
Instead of calling xen_hvm_init_shared_info() on boot and resume split it up into a boot time function searching for the pfn to use and a mapping function doing the hypervisor mapping call. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-06-25xen: allocate page for shared info page from low memoryJuergen Gross
In a HVM guest the kernel allocates the page for mapping the shared info structure via extend_brk() today. This will lead to a drop of performance as the underlying EPT entry will have to be split up into 4kB entries as the single shared info page is located in hypervisor memory. The issue has been detected by using the libmicro munmap test: unmapping 8kB of memory was faster by nearly a factor of two when no pv interfaces were active in the HVM guest. So instead of taking a page from memory which might be mapped via large EPT entries use a page which is already mapped via a 4kB EPT entry: we can take a page from the first 1MB of memory as the video memory at 640kB disallows using larger EPT entries. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-06-13xen/vcpu: Handle xen_vcpu_setup() failure in hotplugAnkur Arora
The hypercall VCPUOP_register_vcpu_info can fail. This failure is handled by making per_cpu(xen_vcpu, cpu) point to its shared_info slot and those without one (cpu >= MAX_VIRT_CPUS) be NULL. For PVH/PVHVM, this is not enough, because we also need to pull these VCPUs out of circulation. Fix for PVH/PVHVM: on registration failure in the cpuhp prepare callback (xen_cpu_up_prepare_hvm()), return an error to the cpuhp state-machine so it can fail the CPU init. Fix for PV: the registration happens before smp_init(), so, in the failure case we clamp setup_max_cpus and limit the number of VCPUs that smp_init() will bring-up to MAX_VIRT_CPUS. This is functionally correct but it makes the code a bit simpler if we get rid of this explicit clamping: for VCPUs that don't have valid xen_vcpu, fail the CPU init in the cpuhp prepare callback (xen_cpu_up_prepare_pv()). Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-06-13xen/pvh*: Support > 32 VCPUs at domain restoreAnkur Arora
When Xen restores a PVHVM or PVH guest, its shared_info only holds up to 32 CPUs. The hypercall VCPUOP_register_vcpu_info allows us to setup per-page areas for VCPUs. This means we can boot PVH* guests with more than 32 VCPUs. During restore the per-cpu structure is allocated freshly by the hypervisor (vcpu_info_mfn is set to INVALID_MFN) so that the newly restored guest can make a VCPUOP_register_vcpu_info hypercall. However, we end up triggering this condition in Xen: /* Run this command on yourself or on other offline VCPUS. */ if ( (v != current) && !test_bit(_VPF_down, &v->pause_flags) ) which means we are unable to setup the per-cpu VCPU structures for running VCPUS. The Linux PV code paths makes this work by iterating over cpu_possible in xen_vcpu_restore() with: 1) is target CPU up (VCPUOP_is_up hypercall?) 2) if yes, then VCPUOP_down to pause it 3) VCPUOP_register_vcpu_info 4) if it was down, then VCPUOP_up to bring it back up With Xen commit 192df6f9122d ("xen/x86: allow HVM guests to use hypercalls to bring up vCPUs") this is available for non-PV guests. As such first check if VCPUOP_is_up is actually possible before trying this dance. As most of this dance code is done already in xen_vcpu_restore() let's make it callable on PV, PVH and PVHVM. Based-on-patch-by: Konrad Wilk <konrad.wilk@oracle.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-06-13xen/vcpu: Simplify xen_vcpu related codeAnkur Arora
Largely mechanical changes to aid unification of xen_vcpu_restore() logic for PV, PVH and PVHVM. xen_vcpu_setup(): the only change in logic is that clamp_max_cpus() is now handled inside the "if (!xen_have_vcpu_info_placement)" block. xen_vcpu_restore(): code movement from enlighten_pv.c to enlighten.c. xen_vcpu_info_reset(): pulls together all the code where xen_vcpu is set to default. Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-05-03xen: Move xen_have_vector_callback definition to enlighten.cBoris Ostrovsky
Commit 84d582d236dc ("xen: Revert commits da72ff5bfcb0 and 72a9b186292d") defined xen_have_vector_callback in enlighten_hvm.c. Since guest-type-neutral code refers to this variable this causes build failures when CONFIG_XEN_PVHVM is not defined. Moving xen_have_vector_callback definition to enlighten.c resolves this issue. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reported-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-05-02xen: Revert commits da72ff5bfcb0 and 72a9b186292dBoris Ostrovsky
Recent discussion (http://marc.info/?l=xen-devel&m=149192184523741) established that commit 72a9b186292d ("xen: Remove event channel notification through Xen PCI platform device") (and thus commit da72ff5bfcb0 ("partially revert "xen: Remove event channel notification through Xen PCI platform device"")) are unnecessary and, in fact, prevent HVM guests from booting on Xen releases prior to 4.0 Therefore we revert both of those commits. The summary of that discussion is below: Here is the brief summary of the current situation: Before the offending commit (72a9b186292): 1) INTx does not work because of the reset_watches path. 2) The reset_watches path is only taken if you have Xen > 4.0 3) The Linux Kernel by default will use vector inject if the hypervisor support. So even INTx does not work no body running the kernel with Xen > 4.0 would notice. Unless he explicitly disabled this feature either in the kernel or in Xen (and this can only be disabled by modifying the code, not user-supported way to do it). After the offending commit (+ partial revert): 1) INTx is no longer support for HVM (only for PV guests). 2) Any HVM guest The kernel will not boot on Xen < 4.0 which does not have vector injection support. Since the only other mode supported is INTx which. So based on this summary, I think before commit (72a9b186292) we were in much better position from a user point of view. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-05-02x86/xen: split off enlighten_hvm.cVitaly Kuznetsov
Move PVHVM related code to enlighten_hvm.c. Three functions: xen_cpuhp_setup(), xen_reboot(), xen_emergency_restart() are shared, drop static qualifier from them. These functions will go to common code once it is split from enlighten.c. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>