x86/HVM: expose VM assist hypercall

In preparation for the addition of VMASST_TYPE_runstate_update_flag
commit 72c538cca957 ("arm: add support for vm_assist hypercall") enabled
the hypercall for Arm. I consider it not logical that it then isn't also
exposed to x86 HVM guests (with the same single feature permitted to be
enabled as Arm has); Linux actually tries to use it afaict.

Rather than introducing yet another thin wrapper around vm_assist(),
make that function the main handler, requiring a per-arch
arch_vm_assist_valid_mask() definition instead.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index a008d7df1ceeff7c1e835cdf25ab43fc432725ea..7f18f4a88aa5d3592fd8038339b93e928dc13ec0 100644 (file)
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -939,6 +939,9 @@ int arch_set_info_guest(
         v->arch.dr6 = c(debugreg[6]);
         v->arch.dr7 = c(debugreg[7]);
 
+        if ( v->vcpu_id == 0 )
+            d->vm_assist = c.nat->vm_assist;
+
         hvm_set_info_guest(v);
         goto out;
     }

diff --git a/xen/arch/x86/hvm/hypercall.c b/xen/arch/x86/hvm/hypercall.c
index cedc7f2ac53f4096b0a5b69f2e4f30ab21b538f7..b4a0aeab50bdf5c3b9ab5db94f9204b75c06e17e 100644 (file)
--- a/xen/arch/x86/hvm/hypercall.c
+++ b/xen/arch/x86/hvm/hypercall.c
@@ -128,6 +128,7 @@ static const hypercall_table_t hvm_hypercall_table[] = {
 #ifdef CONFIG_GRANT_TABLE
     HVM_CALL(grant_table_op),
 #endif
+    HYPERCALL(vm_assist),
     COMPAT_CALL(vcpu_op),
     HVM_CALL(physdev_op),
     COMPAT_CALL(xen_version),

diff --git a/xen/arch/x86/pv/hypercall.c b/xen/arch/x86/pv/hypercall.c
index 17ddf9ea1f6e11e78890acc4b22bfb19774f1829..686a7f2c5c09476db2936138c5e96fc50b40246d 100644 (file)
--- a/xen/arch/x86/pv/hypercall.c
+++ b/xen/arch/x86/pv/hypercall.c
@@ -57,7 +57,7 @@ const hypercall_table_t pv_hypercall_table[] = {
 #ifdef CONFIG_GRANT_TABLE
     COMPAT_CALL(grant_table_op),
 #endif
-    COMPAT_CALL(vm_assist),
+    HYPERCALL(vm_assist),
     COMPAT_CALL(update_va_mapping_otherdomain),
     COMPAT_CALL(iret),
     COMPAT_CALL(vcpu_op),

diff --git a/xen/common/compat/kernel.c b/xen/common/compat/kernel.c
index 5c6e7322f804bda5e30c69e916b7d10ea7bb1268..804b919bdc72892a84732ef36d452c68981caf26 100644 (file)
--- a/xen/common/compat/kernel.c
+++ b/xen/common/compat/kernel.c
@@ -37,11 +37,6 @@ CHECK_TYPE(capabilities_info);
 
 CHECK_TYPE(domain_handle);
 
-#ifdef COMPAT_VM_ASSIST_VALID
-#undef VM_ASSIST_VALID
-#define VM_ASSIST_VALID COMPAT_VM_ASSIST_VALID
-#endif
-
 #define DO(fn) int compat_##fn
 #define COMPAT
 

diff --git a/xen/common/domain.c b/xen/common/domain.c
index 3dcd73f67c3c44700a3627bab6d4909bf965e496..7cc9526139a68146e21a3a3734f4ef352d8d9dda 100644 (file)
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -1517,20 +1517,23 @@ long do_vcpu_op(int cmd, unsigned int vcpuid, XEN_GUEST_HANDLE_PARAM(void) arg)
     return rc;
 }
 
-#ifdef VM_ASSIST_VALID
-long vm_assist(struct domain *p, unsigned int cmd, unsigned int type,
-               unsigned long valid)
+#ifdef arch_vm_assist_valid_mask
+long do_vm_assist(unsigned int cmd, unsigned int type)
 {
+    struct domain *currd = current->domain;
+    const unsigned long valid = arch_vm_assist_valid_mask(currd);
+
     if ( type >= BITS_PER_LONG || !test_bit(type, &valid) )
         return -EINVAL;
 
     switch ( cmd )
     {
     case VMASST_CMD_enable:
-        set_bit(type, &p->vm_assist);
+        set_bit(type, &currd->vm_assist);
         return 0;
+
     case VMASST_CMD_disable:
-        clear_bit(type, &p->vm_assist);
+        clear_bit(type, &currd->vm_assist);
         return 0;
     }
 

diff --git a/xen/common/kernel.c b/xen/common/kernel.c
index 22941cec94c668a26b3b722611e9518b7bc2ea84..572e3fc07d18bff0dd60cc88c7278a7febd958f9 100644 (file)
--- a/xen/common/kernel.c
+++ b/xen/common/kernel.c
@@ -566,13 +566,6 @@ DO(xen_version)(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
     return -ENOSYS;
 }
 
-#ifdef VM_ASSIST_VALID
-DO(vm_assist)(unsigned int cmd, unsigned int type)
-{
-    return vm_assist(current->domain, cmd, type, VM_ASSIST_VALID);
-}
-#endif
-
 /*
  * Local variables:
  * mode: C

diff --git a/xen/include/asm-arm/config.h b/xen/include/asm-arm/config.h
index bc89e84f4d67abf1e1dd37d72046bba2c36bc0ea..fbb4b23a6929fea89f07a8a5c6b25c541a20e824 100644 (file)
--- a/xen/include/asm-arm/config.h
+++ b/xen/include/asm-arm/config.h
@@ -195,8 +195,6 @@ extern unsigned long frametable_virt_end;
 #define watchdog_disable() ((void)0)
 #define watchdog_enable()  ((void)0)
 
-#define VM_ASSIST_VALID          (1UL << VMASST_TYPE_runstate_update_flag)
-
 #endif /* __ARM_CONFIG_H__ */
 /*
  * Local variables:

diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index d2142c6707eb8f30195aa49fe7d1dcfc5a125c76..4e2f582006a53c40fbb86e4e1a11a8356f605b13 100644 (file)
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -262,6 +262,8 @@ static inline void free_vcpu_guest_context(struct vcpu_guest_context *vgc)
 
 static inline void arch_vcpu_block(struct vcpu *v) {}
 
+#define arch_vm_assist_valid_mask(d) (1UL << VMASST_TYPE_runstate_update_flag)
+
 #endif /* __ASM_DOMAIN_H__ */
 
 /*

diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h
index a34053c4c0f2d3baa7a250096a892b45a412ca86..2d6393e64ea4500d7014e8f3fb05c662f8f067a4 100644 (file)
--- a/xen/include/asm-x86/config.h
+++ b/xen/include/asm-x86/config.h
@@ -309,17 +309,6 @@ extern unsigned long xen_phys_start;
 #define ARG_XLAT_START(v)        \
     (ARG_XLAT_VIRT_START + ((v)->vcpu_id << ARG_XLAT_VA_SHIFT))
 
-#define NATIVE_VM_ASSIST_VALID   ((1UL << VMASST_TYPE_4gb_segments)        | \
-                                  (1UL << VMASST_TYPE_4gb_segments_notify) | \
-                                  (1UL << VMASST_TYPE_writable_pagetables) | \
-                                  (1UL << VMASST_TYPE_pae_extended_cr3)    | \
-                                  (1UL << VMASST_TYPE_architectural_iopl)  | \
-                                  (1UL << VMASST_TYPE_runstate_update_flag)| \
-                                  (1UL << VMASST_TYPE_m2p_strict))
-#define VM_ASSIST_VALID          NATIVE_VM_ASSIST_VALID
-#define COMPAT_VM_ASSIST_VALID   (NATIVE_VM_ASSIST_VALID & \
-                                  ((1UL << COMPAT_BITS_PER_LONG) - 1))
-
 #define ELFSIZE 64
 
 #define ARCH_CRASH_SAVE_VMCOREINFO

diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index 1e409c665db6d69ebafa6f98bc40e8c3aca93493..b10d74fb575baa7ec8c7babce0d9706e85efaa5f 100644 (file)
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -701,6 +701,25 @@ static inline void pv_inject_sw_interrupt(unsigned int vector)
     pv_inject_event(&event);
 }
 
+#define PV32_VM_ASSIST_MASK ((1UL << VMASST_TYPE_4gb_segments)        | \
+                             (1UL << VMASST_TYPE_4gb_segments_notify) | \
+                             (1UL << VMASST_TYPE_writable_pagetables) | \
+                             (1UL << VMASST_TYPE_pae_extended_cr3)    | \
+                             (1UL << VMASST_TYPE_architectural_iopl)  | \
+                             (1UL << VMASST_TYPE_runstate_update_flag))
+/*
+ * Various of what PV32_VM_ASSIST_MASK has isn't really applicable to 64-bit,
+ * but we can't make such requests fail all of the sudden.
+ */
+#define PV64_VM_ASSIST_MASK (PV32_VM_ASSIST_MASK                      | \
+                             (1UL << VMASST_TYPE_m2p_strict))
+#define HVM_VM_ASSIST_MASK  (1UL << VMASST_TYPE_runstate_update_flag)
+
+#define arch_vm_assist_valid_mask(d) \
+    (is_hvm_domain(d) ? HVM_VM_ASSIST_MASK \
+                      : is_pv_32bit_domain(d) ? PV32_VM_ASSIST_MASK \
+                                              : PV64_VM_ASSIST_MASK)
+
 #endif /* __ASM_DOMAIN_H__ */
 
 /*

diff --git a/xen/include/xen/hypercall.h b/xen/include/xen/hypercall.h
index ad8ad27b239ab039340e9c99c3eb3db912f1ba2f..d82a293377740681802b7dde016964890c140d4a 100644 (file)
--- a/xen/include/xen/hypercall.h
+++ b/xen/include/xen/hypercall.h
@@ -192,8 +192,6 @@ extern int compat_xsm_op(
 
 extern int compat_kexec_op(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) uarg);
 
-extern int compat_vm_assist(unsigned int cmd, unsigned int type);
-
 DEFINE_XEN_GUEST_HANDLE(multicall_entry_compat_t);
 extern int compat_multicall(
     XEN_GUEST_HANDLE_PARAM(multicall_entry_compat_t) call_list,

diff --git a/xen/include/xen/lib.h b/xen/include/xen/lib.h
index 5d718bbdba309e3cb5917264a79b8919e32ba4ff..2d7a054931c75d56447ac2bf6025447f1dad26b5 100644 (file)
--- a/xen/include/xen/lib.h
+++ b/xen/include/xen/lib.h
@@ -122,8 +122,6 @@ extern void guest_printk(const struct domain *d, const char *format, ...)
     __attribute__ ((format (printf, 2, 3)));
 extern void noreturn panic(const char *format, ...)
     __attribute__ ((format (printf, 1, 2)));
-extern long vm_assist(struct domain *, unsigned int cmd, unsigned int type,
-                      unsigned long valid);
 extern int __printk_ratelimit(int ratelimit_ms, int ratelimit_burst);
 extern int printk_ratelimit(void);