From db2832309a82b9acc4b8cc33a1831d36507ec13e Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Fri, 24 Nov 2023 08:48:52 +0100 Subject: [PATCH 1/2] x86/xen: fix percpu vcpu_info allocation Today the percpu struct vcpu_info is allocated via DEFINE_PER_CPU(), meaning that it could cross a page boundary. In this case registering it with the hypervisor will fail, resulting in a panic(). This can easily be fixed by using DEFINE_PER_CPU_ALIGNED() instead, as struct vcpu_info is guaranteed to have a size of 64 bytes, matching the cache line size of x86 64-bit processors (Xen doesn't support 32-bit processors). Fixes: 5ead97c84fa7 ("xen: Core Xen implementation") Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20231124074852.25161-1-jgross@suse.com Signed-off-by: Juergen Gross --- arch/x86/xen/enlighten.c | 6 +++++- arch/x86/xen/xen-ops.h | 2 +- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 0337392a31214..3c61bb98c10e2 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -33,9 +33,12 @@ EXPORT_SYMBOL_GPL(hypercall_page); * and xen_vcpu_setup for details. By default it points to share_info->vcpu_info * but during boot it is switched to point to xen_vcpu_info. * The pointer is used in xen_evtchn_do_upcall to acknowledge pending events. + * Make sure that xen_vcpu_info doesn't cross a page boundary by making it + * cache-line aligned (the struct is guaranteed to have a size of 64 bytes, + * which matches the cache line size of 64-bit x86 processors). */ DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu); -DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info); +DEFINE_PER_CPU_ALIGNED(struct vcpu_info, xen_vcpu_info); /* Linux <-> Xen vCPU id mapping */ DEFINE_PER_CPU(uint32_t, xen_vcpu_id); @@ -160,6 +163,7 @@ void xen_vcpu_setup(int cpu) int err; struct vcpu_info *vcpup; + BUILD_BUG_ON(sizeof(*vcpup) > SMP_CACHE_BYTES); BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info); /* diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index 408a2aa66c692..a87ab36889e76 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -21,7 +21,7 @@ extern void *xen_initial_gdt; struct trap_info; void xen_copy_trap_info(struct trap_info *traps); -DECLARE_PER_CPU(struct vcpu_info, xen_vcpu_info); +DECLARE_PER_CPU_ALIGNED(struct vcpu_info, xen_vcpu_info); DECLARE_PER_CPU(unsigned long, xen_cr3); DECLARE_PER_CPU(unsigned long, xen_current_cr3); From 7f3da4b698bcc21a6df0e7f114af71d53a3e26ac Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 28 Nov 2023 09:52:41 +0300 Subject: [PATCH 2/2] xen/events: fix error code in xen_bind_pirq_msi_to_irq() Return -ENOMEM if xen_irq_init() fails. currently the code returns an uninitialized variable or zero. Fixes: 5dd9ad32d775 ("xen/events: drop xen_allocate_irqs_dynamic()") Signed-off-by: Dan Carpenter Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/3b9ab040-a92e-4e35-b687-3a95890a9ace@moroto.mountain Signed-off-by: Juergen Gross --- drivers/xen/events/events_base.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index f5edb9e27e3ca..b8cfea7812d6b 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -1110,8 +1110,10 @@ int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc, for (i = 0; i < nvec; i++) { info = xen_irq_init(irq + i); - if (!info) + if (!info) { + ret = -ENOMEM; goto error_irq; + } irq_set_chip_and_handler_name(irq + i, &xen_pirq_chip, handle_edge_irq, name);