Re: [PATCH] x86/ioperm: add new paravirt function update_io_bitmap

Friendly ping...

On 18.02.20 16:47, Juergen Gross wrote:

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 Cc: stable@vger.kernel.org # 5.5 Signed-off-by: Juergen Gross jgross@suse.com Reviewed-by: Jan Beulich jbeulich@suse.com Tested-by: Jan Beulich jbeulich@suse.com

---

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(-)

diff --git a/arch/x86/include/asm/io_bitmap.h b/arch/x86/include/asm/io_bitmap.h index 02c6ef8f7667..07344d82e88e 100644 --- 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) { }

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index 86e7317eb31f..694d8daf4983 100644 --- 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_desc *dt, int entry, const gate_desc *g) 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) {

diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index 84812964d3dd..732f62e04ddb 100644 --- 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 */ diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index 789f5e4f89de..c131ba4e70ef 100644 --- 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,

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 839b5244e3b7..3053c85e0e42 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -374,7 +374,7 @@ static void tss_copy_io_bitmap(struct tss_struct *tss, struct io_bitmap *iobm) /**

• 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 = &current->thread; diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index 1f756ffffe8b..feaf2e68ee5c 100644 --- 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 sp0) 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) { }

@@ -1046,6 +1068,9 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = { .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 */