Re: [Xen-devel] [PATCH 08/22] mini-os: initialize trap handling for HVMlite

2016-08-23 Thread Samuel Thibault 
Juergen Gross, on Tue 23 Aug 2016 17:15:54 +0200, wrote:
> Trap handling for HVMlite domains requires an initialized IDT.
> 
> Signed-off-by: Juergen Gross 

Reviewed-by: Samuel Thibault 

> ---
>  arch/x86/setup.c  | 15 --
>  arch/x86/traps.c  | 88 
> +++
>  arch/x86/x86_64.S |  4 +++
>  include/x86/os.h  |  1 +
>  4 files changed, 93 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/x86/setup.c b/arch/x86/setup.c
> index edc4ca4..efecefb 100644
> --- a/arch/x86/setup.c
> +++ b/arch/x86/setup.c
> @@ -52,10 +52,6 @@ char stack[2*STACK_SIZE];
>  
>  extern char shared_info[PAGE_SIZE];
>  
> -/* Assembler interface fns in entry.S. */
> -void hypervisor_callback(void);
> -void failsafe_callback(void);
> -
>  #if defined(__x86_64__)
>  #define __pte(x) ((pte_t) { (x) } )
>  #else
> @@ -162,17 +158,6 @@ arch_init(void *par)
>   /* Grab the shared_info pointer and put it in a safe place. */
>   HYPERVISOR_shared_info = map_shared_info(start_info.shared_info);
>  
> - /* Set up event and failsafe callback addresses. */
> -#ifdef __i386__
> - HYPERVISOR_set_callbacks(
> - __KERNEL_CS, (unsigned long)hypervisor_callback,
> - __KERNEL_CS, (unsigned long)failsafe_callback);
> -#else
> - HYPERVISOR_set_callbacks(
> - (unsigned long)hypervisor_callback,
> - (unsigned long)failsafe_callback, 0);
> -#endif
> -
>   start_kernel();
>  }
>  
> diff --git a/arch/x86/traps.c b/arch/x86/traps.c
> index 307a14c..3b1fffb 100644
> --- a/arch/x86/traps.c
> +++ b/arch/x86/traps.c
> @@ -1,10 +1,12 @@
>  
>  #include 
>  #include 
> +#include 
>  #include 
>  #include 
>  #include 
>  #include 
> +#include 
>  
>  /*
>   * These are assembler stubs in entry.S.
> @@ -293,6 +295,11 @@ void do_spurious_interrupt_bug(struct pt_regs * regs)
>  {
>  }
>  
> +/* Assembler interface fns in entry.S. */
> +void hypervisor_callback(void);
> +void failsafe_callback(void);
> +
> +#ifdef CONFIG_PARAVIRT
>  /*
>   * Submit a virtual IDT to teh hypervisor. This consists of tuples
>   * (interrupt vector, privilege ring, CS:EIP of handler).
> @@ -325,9 +332,90 @@ static trap_info_t trap_table[] = {
>  void trap_init(void)
>  {
>  HYPERVISOR_set_trap_table(trap_table);
> +
> +#ifdef __i386__
> +HYPERVISOR_set_callbacks(
> +__KERNEL_CS, (unsigned long)hypervisor_callback,
> +__KERNEL_CS, (unsigned long)failsafe_callback);
> +#else
> +HYPERVISOR_set_callbacks(
> +(unsigned long)hypervisor_callback,
> +(unsigned long)failsafe_callback, 0);
> +#endif
>  }
>  
>  void trap_fini(void)
>  {
>  HYPERVISOR_set_trap_table(NULL);
>  }
> +#else
> +
> +#define INTR_STACK_SIZE PAGE_SIZE
> +static uint8_t intr_stack[INTR_STACK_SIZE] __attribute__((aligned(16)));
> +
> +hw_tss tss __attribute__((aligned(16))) =
> +{
> +#if defined(__i386__)
> +.esp0 = (unsigned long)_stack[INTR_STACK_SIZE],
> +.ss0  = __KERN_DS,
> +#elif defined(__x86_64__)
> +.rsp0 = (unsigned long)_stack[INTR_STACK_SIZE],
> +#endif
> +.iopb = X86_TSS_INVALID_IO_BITMAP,
> +};
> +
> +static void setup_gate(unsigned int entry, void *addr, unsigned int dpl)
> +{
> +idt[entry].offset0 = (unsigned long)addr & 0x;
> +idt[entry].selector = __KERN_CS;
> +idt[entry]._r0 = 0;
> +idt[entry].type = 14;
> +idt[entry].s = 0;
> +idt[entry].dpl = dpl;
> +idt[entry].p = 1;
> +idt[entry].offset1 = ((unsigned long)addr >> 16) & 0x;
> +#if defined(__x86_64__)
> +idt[entry].ist = 0;
> +idt[entry].offset2 = ((unsigned long)addr >> 32) & 0xu;
> +idt[entry]._r1 = 0;
> +#endif
> +}
> +
> +void trap_init(void)
> +{
> +setup_gate(TRAP_divide_error, _error, 0);
> +setup_gate(TRAP_debug, , 0);
> +setup_gate(TRAP_int3, , 3);
> +setup_gate(TRAP_overflow, , 3);
> +setup_gate(TRAP_bounds, , 0);
> +setup_gate(TRAP_invalid_op, _op, 0);
> +setup_gate(TRAP_no_device, _not_available, 0);
> +setup_gate(TRAP_copro_seg, _segment_overrun, 0);
> +setup_gate(TRAP_invalid_tss, _TSS, 0);
> +setup_gate(TRAP_no_segment, _not_present, 0);
> +setup_gate(TRAP_stack_error, _segment, 0);
> +setup_gate(TRAP_gp_fault, _protection, 0);
> +setup_gate(TRAP_page_fault, _fault, 0);
> +setup_gate(TRAP_spurious_int, _interrupt_bug, 0);
> +setup_gate(TRAP_copro_error, _error, 0);
> +setup_gate(TRAP_alignment_check, _check, 0);
> +setup_gate(TRAP_simd_error, _coprocessor_error, 0);
> +setup_gate(TRAP_xen_callback, hypervisor_callback, 0);
> +
> +asm volatile ("lidt idt_ptr");
> +
> +gdt[GDTE_TSS] = (typeof(*gdt))INIT_GDTE((unsigned long), 0x67, 0x89);
> +asm volatile ("ltr %w0" :: "rm" (GDTE_TSS * 8));
> +
> +if ( hvm_set_parameter(HVM_PARAM_CALLBACK_IRQ,
> +   (2ULL << 56) | TRAP_xen_callback) )
> +{
> +xprintk("Request for Xen

[Xen-devel] [PATCH 08/22] mini-os: initialize trap handling for HVMlite

2016-08-23 Thread Juergen Gross 
Trap handling for HVMlite domains requires an initialized IDT.

Signed-off-by: Juergen Gross 
---
 arch/x86/setup.c  | 15 --
 arch/x86/traps.c  | 88 +++
 arch/x86/x86_64.S |  4 +++
 include/x86/os.h  |  1 +
 4 files changed, 93 insertions(+), 15 deletions(-)

diff --git a/arch/x86/setup.c b/arch/x86/setup.c
index edc4ca4..efecefb 100644
--- a/arch/x86/setup.c
+++ b/arch/x86/setup.c
@@ -52,10 +52,6 @@ char stack[2*STACK_SIZE];
 
 extern char shared_info[PAGE_SIZE];
 
-/* Assembler interface fns in entry.S. */
-void hypervisor_callback(void);
-void failsafe_callback(void);
-
 #if defined(__x86_64__)
 #define __pte(x) ((pte_t) { (x) } )
 #else
@@ -162,17 +158,6 @@ arch_init(void *par)
/* Grab the shared_info pointer and put it in a safe place. */
HYPERVISOR_shared_info = map_shared_info(start_info.shared_info);
 
-   /* Set up event and failsafe callback addresses. */
-#ifdef __i386__
-   HYPERVISOR_set_callbacks(
-   __KERNEL_CS, (unsigned long)hypervisor_callback,
-   __KERNEL_CS, (unsigned long)failsafe_callback);
-#else
-   HYPERVISOR_set_callbacks(
-   (unsigned long)hypervisor_callback,
-   (unsigned long)failsafe_callback, 0);
-#endif
-
start_kernel();
 }
 
diff --git a/arch/x86/traps.c b/arch/x86/traps.c
index 307a14c..3b1fffb 100644
--- a/arch/x86/traps.c
+++ b/arch/x86/traps.c
@@ -1,10 +1,12 @@
 
 #include 
 #include 
+#include 
 #include 
 #include 
 #include 
 #include 
+#include 
 
 /*
  * These are assembler stubs in entry.S.
@@ -293,6 +295,11 @@ void do_spurious_interrupt_bug(struct pt_regs * regs)
 {
 }
 
+/* Assembler interface fns in entry.S. */
+void hypervisor_callback(void);
+void failsafe_callback(void);
+
+#ifdef CONFIG_PARAVIRT
 /*
  * Submit a virtual IDT to teh hypervisor. This consists of tuples
  * (interrupt vector, privilege ring, CS:EIP of handler).
@@ -325,9 +332,90 @@ static trap_info_t trap_table[] = {
 void trap_init(void)
 {
 HYPERVISOR_set_trap_table(trap_table);
+
+#ifdef __i386__
+HYPERVISOR_set_callbacks(
+__KERNEL_CS, (unsigned long)hypervisor_callback,
+__KERNEL_CS, (unsigned long)failsafe_callback);
+#else
+HYPERVISOR_set_callbacks(
+(unsigned long)hypervisor_callback,
+(unsigned long)failsafe_callback, 0);
+#endif
 }
 
 void trap_fini(void)
 {
 HYPERVISOR_set_trap_table(NULL);
 }
+#else
+
+#define INTR_STACK_SIZE PAGE_SIZE
+static uint8_t intr_stack[INTR_STACK_SIZE] __attribute__((aligned(16)));
+
+hw_tss tss __attribute__((aligned(16))) =
+{
+#if defined(__i386__)
+.esp0 = (unsigned long)_stack[INTR_STACK_SIZE],
+.ss0  = __KERN_DS,
+#elif defined(__x86_64__)
+.rsp0 = (unsigned long)_stack[INTR_STACK_SIZE],
+#endif
+.iopb = X86_TSS_INVALID_IO_BITMAP,
+};
+
+static void setup_gate(unsigned int entry, void *addr, unsigned int dpl)
+{
+idt[entry].offset0 = (unsigned long)addr & 0x;
+idt[entry].selector = __KERN_CS;
+idt[entry]._r0 = 0;
+idt[entry].type = 14;
+idt[entry].s = 0;
+idt[entry].dpl = dpl;
+idt[entry].p = 1;
+idt[entry].offset1 = ((unsigned long)addr >> 16) & 0x;
+#if defined(__x86_64__)
+idt[entry].ist = 0;
+idt[entry].offset2 = ((unsigned long)addr >> 32) & 0xu;
+idt[entry]._r1 = 0;
+#endif
+}
+
+void trap_init(void)
+{
+setup_gate(TRAP_divide_error, _error, 0);
+setup_gate(TRAP_debug, , 0);
+setup_gate(TRAP_int3, , 3);
+setup_gate(TRAP_overflow, , 3);
+setup_gate(TRAP_bounds, , 0);
+setup_gate(TRAP_invalid_op, _op, 0);
+setup_gate(TRAP_no_device, _not_available, 0);
+setup_gate(TRAP_copro_seg, _segment_overrun, 0);
+setup_gate(TRAP_invalid_tss, _TSS, 0);
+setup_gate(TRAP_no_segment, _not_present, 0);
+setup_gate(TRAP_stack_error, _segment, 0);
+setup_gate(TRAP_gp_fault, _protection, 0);
+setup_gate(TRAP_page_fault, _fault, 0);
+setup_gate(TRAP_spurious_int, _interrupt_bug, 0);
+setup_gate(TRAP_copro_error, _error, 0);
+setup_gate(TRAP_alignment_check, _check, 0);
+setup_gate(TRAP_simd_error, _coprocessor_error, 0);
+setup_gate(TRAP_xen_callback, hypervisor_callback, 0);
+
+asm volatile ("lidt idt_ptr");
+
+gdt[GDTE_TSS] = (typeof(*gdt))INIT_GDTE((unsigned long), 0x67, 0x89);
+asm volatile ("ltr %w0" :: "rm" (GDTE_TSS * 8));
+
+if ( hvm_set_parameter(HVM_PARAM_CALLBACK_IRQ,
+   (2ULL << 56) | TRAP_xen_callback) )
+{
+xprintk("Request for Xen HVM callback vector failed\n");
+do_exit();
+}
+}
+
+void trap_fini(void)
+{
+}
+#endif
diff --git a/arch/x86/x86_64.S b/arch/x86/x86_64.S
index 373f400..e725c63 100644
--- a/arch/x86/x86_64.S
+++ b/arch/x86/x86_64.S
@@ -130,18 +130,22 @@ KERNEL_CS_MASK = 0xfc
 .endm
 
 .macro HYPERVISOR_IRET flag
+#ifdef CONFIG_PARAVIRT
testl $NMI_MASK,2*8(%rsp)
jnz   2f
+#endif
 
/* Direct