From: Juergen Gross jgross@suse.com
commit 99bcd4a6e5b8ba201fdd252f1054689884899fee upstream.
Commit 111e7b15cf10f6 ("x86/ioperm: Extend IOPL config to control ioperm() as well") reworked the iopl syscall to use I/O bitmaps.
Unfortunately this broke Xen PV domains using that syscall as there is currently no I/O bitmap support in PV domains.
Add I/O bitmap support via a new paravirt function update_io_bitmap which Xen PV domains can use to update their I/O bitmaps via a hypercall.
Fixes: 111e7b15cf10f6 ("x86/ioperm: Extend IOPL config to control ioperm() as well") Reported-by: Jan Beulich jbeulich@suse.com Signed-off-by: Juergen Gross jgross@suse.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Tested-by: Jan Beulich jbeulich@suse.com Reviewed-by: Jan Beulich jbeulich@suse.com Cc: stable@vger.kernel.org # 5.5 Link: https://lkml.kernel.org/r/20200218154712.25490-1-jgross@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/include/asm/io_bitmap.h | 9 ++++++++- arch/x86/include/asm/paravirt.h | 7 +++++++ arch/x86/include/asm/paravirt_types.h | 4 ++++ arch/x86/kernel/paravirt.c | 5 +++++ arch/x86/kernel/process.c | 2 +- arch/x86/xen/enlighten_pv.c | 25 +++++++++++++++++++++++++ 6 files changed, 50 insertions(+), 2 deletions(-)
--- a/arch/x86/include/asm/io_bitmap.h +++ b/arch/x86/include/asm/io_bitmap.h @@ -19,7 +19,14 @@ struct task_struct; void io_bitmap_share(struct task_struct *tsk); void io_bitmap_exit(void);
-void tss_update_io_bitmap(void); +void native_tss_update_io_bitmap(void); + +#ifdef CONFIG_PARAVIRT_XXL +#include <asm/paravirt.h> +#else +#define tss_update_io_bitmap native_tss_update_io_bitmap +#endif + #else static inline void io_bitmap_share(struct task_struct *tsk) { } static inline void io_bitmap_exit(void) { } --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -295,6 +295,13 @@ static inline void write_idt_entry(gate_ PVOP_VCALL3(cpu.write_idt_entry, dt, entry, g); }
+#ifdef CONFIG_X86_IOPL_IOPERM +static inline void tss_update_io_bitmap(void) +{ + PVOP_VCALL0(cpu.update_io_bitmap); +} +#endif + static inline void paravirt_activate_mm(struct mm_struct *prev, struct mm_struct *next) { --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -140,6 +140,10 @@ struct pv_cpu_ops {
void (*load_sp0)(unsigned long sp0);
+#ifdef CONFIG_X86_IOPL_IOPERM + void (*update_io_bitmap)(void); +#endif + void (*wbinvd)(void);
/* cpuid emulation, mostly so that caps bits can be disabled */ --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -30,6 +30,7 @@ #include <asm/timer.h> #include <asm/special_insns.h> #include <asm/tlb.h> +#include <asm/io_bitmap.h>
/* * nop stub, which must not clobber anything *including the stack* to @@ -341,6 +342,10 @@ struct paravirt_patch_template pv_ops = .cpu.iret = native_iret, .cpu.swapgs = native_swapgs,
+#ifdef CONFIG_X86_IOPL_IOPERM + .cpu.update_io_bitmap = native_tss_update_io_bitmap, +#endif + .cpu.start_context_switch = paravirt_nop, .cpu.end_context_switch = paravirt_nop,
--- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -374,7 +374,7 @@ static void tss_copy_io_bitmap(struct ts /** * tss_update_io_bitmap - Update I/O bitmap before exiting to usermode */ -void tss_update_io_bitmap(void) +void native_tss_update_io_bitmap(void) { struct tss_struct *tss = this_cpu_ptr(&cpu_tss_rw); struct thread_struct *t = ¤t->thread; --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -72,6 +72,9 @@ #include <asm/mwait.h> #include <asm/pci_x86.h> #include <asm/cpu.h> +#ifdef CONFIG_X86_IOPL_IOPERM +#include <asm/io_bitmap.h> +#endif
#ifdef CONFIG_ACPI #include <linux/acpi.h> @@ -837,6 +840,25 @@ static void xen_load_sp0(unsigned long s this_cpu_write(cpu_tss_rw.x86_tss.sp0, sp0); }
+#ifdef CONFIG_X86_IOPL_IOPERM +static void xen_update_io_bitmap(void) +{ + struct physdev_set_iobitmap iobitmap; + struct tss_struct *tss = this_cpu_ptr(&cpu_tss_rw); + + native_tss_update_io_bitmap(); + + iobitmap.bitmap = (uint8_t *)(&tss->x86_tss) + + tss->x86_tss.io_bitmap_base; + if (tss->x86_tss.io_bitmap_base == IO_BITMAP_OFFSET_INVALID) + iobitmap.nr_ports = 0; + else + iobitmap.nr_ports = IO_BITMAP_BITS; + + HYPERVISOR_physdev_op(PHYSDEVOP_set_iobitmap, &iobitmap); +} +#endif + static void xen_io_delay(void) { } @@ -1047,6 +1069,9 @@ static const struct pv_cpu_ops xen_cpu_o .write_idt_entry = xen_write_idt_entry, .load_sp0 = xen_load_sp0,
+#ifdef CONFIG_X86_IOPL_IOPERM + .update_io_bitmap = xen_update_io_bitmap, +#endif .io_delay = xen_io_delay,
/* Xen takes care of %gs when switching to usermode for us */