xen/arm64: Remove vreg_emulate_sysreg32

According to ARMv8A architecture, AArch64 registers are 64bit wide
even though in many cases the upper 32bit is reserved. Therefore there
is no need for function vreg_emulate_sysreg32 on arm64. This means
that we can have just one function vreg_emulate_sysreg using new
function pointer:

typedef bool (*vreg_reg_fn_t)(struct cpu_user_regs *regs,
                              register_t *r, bool read);

Modify vreg_emulate_cp32 to use the new function pointer as well.

This change allows to properly use 64bit registers in AArch64 state.
In case of AArch32 the documentation (D1.20.2, DDI 0487A.j) states
that "the upper 32 bits either become zero, or hold the value that
the same architectural register held before any AArch32 execution." As
the choice between them is IMPLEMENTATION DEFINED we cannot assume they
are zeroed. Xen should ensure that but currently it does not. This is
not a new bug and must be fixed as agreed during a discussion over this
patch.

Take the opportunity to switch CNTx_CTL_* to use UL to avoid any
surprise with the negation of any bits (as used in vtimer_cntp_ctl)

Signed-off-by: Michal Orzel <michal.orzel@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>

diff --git a/xen/arch/arm/arm64/vsysreg.c b/xen/arch/arm/arm64/vsysreg.c
index 887266dd46782a58c027ef8f4643d116030bcd64..cf555440819641f43b0c28d4a5fe7d81d8178d28 100644 (file)
--- a/xen/arch/arm/arm64/vsysreg.c
+++ b/xen/arch/arm/arm64/vsysreg.c
@@ -64,7 +64,7 @@ TVM_REG(CONTEXTIDR_EL1)
     {                                                                   \
         bool res;                                                       \
                                                                         \
-        res = vreg_emulate_sysreg64(regs, hsr, vreg_emulate_##reg);     \
+        res = vreg_emulate_sysreg(regs, hsr, vreg_emulate_##reg);       \
         ASSERT(res);                                                    \
         break;                                                          \
     }

diff --git a/xen/arch/arm/vcpreg.c b/xen/arch/arm/vcpreg.c
index 33259c4194977785c4bb5529785cfba0bcb71fb1..dfc18d12ffc3c9f7f0343c5d3c5aed7818d32b75 100644 (file)
--- a/xen/arch/arm/vcpreg.c
+++ b/xen/arch/arm/vcpreg.c
@@ -57,9 +57,17 @@
 #define WRITE_SYSREG_SZ(sz, val, sysreg...)  WRITE_SYSREG##sz(val, sysreg)
 #endif
 
+/*
+ * type32_t is defined as register_t due to the vreg_emulate_cp32 and
+ * vreg_emulate_sysreg taking function pointer with register_t type used for
+ * passing register's value.
+ */
+typedef register_t type32_t;
+typedef uint64_t type64_t;
+
 /* The name is passed from the upper macro to workaround macro expansion. */
 #define TVM_REG(sz, func, reg...)                                           \
-static bool func(struct cpu_user_regs *regs, uint##sz##_t *r, bool read)    \
+static bool func(struct cpu_user_regs *regs, type##sz##_t *r, bool read)    \
 {                                                                           \
     struct vcpu *v = current;                                               \
     bool cache_enabled = vcpu_has_cache_enabled(v);                         \
@@ -83,7 +91,7 @@ static bool func(struct cpu_user_regs *regs, uint##sz##_t *r, bool read)    \
 
 #else /* CONFIG_ARM_64 */
 #define TVM_REG32_COMBINED(lowreg, hireg, xreg)                             \
-static bool vreg_emulate_##xreg(struct cpu_user_regs *regs, uint32_t *r,    \
+static bool vreg_emulate_##xreg(struct cpu_user_regs *regs, register_t *r,  \
                                 bool read, bool hi)                         \
 {                                                                           \
     struct vcpu *v = current;                                               \
@@ -108,13 +116,13 @@ static bool vreg_emulate_##xreg(struct cpu_user_regs *regs, uint32_t *r,    \
     return true;                                                            \
 }                                                                           \
                                                                             \
-static bool vreg_emulate_##lowreg(struct cpu_user_regs *regs, uint32_t *r,  \
+static bool vreg_emulate_##lowreg(struct cpu_user_regs *regs, register_t *r,\
                                   bool read)                                \
 {                                                                           \
     return vreg_emulate_##xreg(regs, r, read, false);                       \
 }                                                                           \
                                                                             \
-static bool vreg_emulate_##hireg(struct cpu_user_regs *regs, uint32_t *r,   \
+static bool vreg_emulate_##hireg(struct cpu_user_regs *regs, register_t *r, \
                                  bool read)                                 \
 {                                                                           \
     return vreg_emulate_##xreg(regs, r, read, true);                        \

diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c
index 613f37abab5e1bbe22a69e14acae666fa3f34a7a..cb5a70c42e3144ad4079fddc11f8183a03cf586e 100644 (file)
--- a/xen/arch/arm/vgic-v3.c
+++ b/xen/arch/arm/vgic-v3.c
@@ -1531,7 +1531,7 @@ static bool vgic_v3_emulate_sysreg(struct cpu_user_regs *regs, union hsr hsr)
     switch ( hsr.bits & HSR_SYSREG_REGS_MASK )
     {
     case HSR_SYSREG_ICC_SGI1R_EL1:
-        return vreg_emulate_sysreg64(regs, hsr, vgic_v3_emulate_sgi1r);
+        return vreg_emulate_sysreg(regs, hsr, vgic_v3_emulate_sgi1r);
 
     default:
         return false;

diff --git a/xen/arch/arm/vtimer.c b/xen/arch/arm/vtimer.c
index 167fc6127a40a3b067df01ecf861ac4863636d85..0196951af4eb5f5ff40d56172bf652612ec2f3f1 100644 (file)
--- a/xen/arch/arm/vtimer.c
+++ b/xen/arch/arm/vtimer.c
@@ -162,7 +162,8 @@ void virt_timer_restore(struct vcpu *v)
     WRITE_SYSREG(v->arch.virt_timer.ctl, CNTV_CTL_EL0);
 }
 
-static bool vtimer_cntp_ctl(struct cpu_user_regs *regs, uint32_t *r, bool read)
+static bool vtimer_cntp_ctl(struct cpu_user_regs *regs, register_t *r,
+                            bool read)
 {
     struct vcpu *v = current;
     s_time_t expires;
@@ -197,7 +198,7 @@ static bool vtimer_cntp_ctl(struct cpu_user_regs *regs, uint32_t *r, bool read)
     return true;
 }
 
-static bool vtimer_cntp_tval(struct cpu_user_regs *regs, uint32_t *r,
+static bool vtimer_cntp_tval(struct cpu_user_regs *regs, register_t *r,
                              bool read)
 {
     struct vcpu *v = current;
@@ -316,11 +317,11 @@ static bool vtimer_emulate_sysreg(struct cpu_user_regs *regs, union hsr hsr)
     switch ( hsr.bits & HSR_SYSREG_REGS_MASK )
     {
     case HSR_SYSREG_CNTP_CTL_EL0:
-        return vreg_emulate_sysreg32(regs, hsr, vtimer_cntp_ctl);
+        return vreg_emulate_sysreg(regs, hsr, vtimer_cntp_ctl);
     case HSR_SYSREG_CNTP_TVAL_EL0:
-        return vreg_emulate_sysreg32(regs, hsr, vtimer_cntp_tval);
+        return vreg_emulate_sysreg(regs, hsr, vtimer_cntp_tval);
     case HSR_SYSREG_CNTP_CVAL_EL0:
-        return vreg_emulate_sysreg64(regs, hsr, vtimer_cntp_cval);
+        return vreg_emulate_sysreg(regs, hsr, vtimer_cntp_cval);
 
     default:
         return false;

diff --git a/xen/include/asm-arm/processor.h b/xen/include/asm-arm/processor.h
index 2577e9a2447c230c13f3a961a75e82505a32c8be..2058b694472851b3d41fb8ddd78c823dc9d04839 100644 (file)
--- a/xen/include/asm-arm/processor.h
+++ b/xen/include/asm-arm/processor.h
@@ -484,9 +484,9 @@ extern register_t __cpu_logical_map[];
 #define CNTKCTL_EL1_EL0PTEN  (1u<<9) /* Expose phys timer registers to EL0 */
 
 /* Timer control registers */
-#define CNTx_CTL_ENABLE   (1u<<0)  /* Enable timer */
+#define CNTx_CTL_ENABLE   (1ul<<0)  /* Enable timer */
 #define CNTx_CTL_MASK     (1ul<<1)  /* Mask IRQ */
-#define CNTx_CTL_PENDING  (1u<<2)  /* IRQ pending */
+#define CNTx_CTL_PENDING  (1ul<<2)  /* IRQ pending */
 
 /* Timer frequency mask */
 #define CNTFRQ_MASK       GENMASK(31, 0)

diff --git a/xen/include/asm-arm/vreg.h b/xen/include/asm-arm/vreg.h
index 1253753833bf511312ef36ba273c019510aeb6b1..fa2f4cdb1782fb32b9a7b72891aac6bd34c87dba 100644 (file)
--- a/xen/include/asm-arm/vreg.h
+++ b/xen/include/asm-arm/vreg.h
@@ -4,13 +4,13 @@
 #ifndef __ASM_ARM_VREG__
 #define __ASM_ARM_VREG__
 
-typedef bool (*vreg_reg32_fn_t)(struct cpu_user_regs *regs, uint32_t *r,
-                                   bool read);
 typedef bool (*vreg_reg64_fn_t)(struct cpu_user_regs *regs, uint64_t *r,
                                    bool read);
+typedef bool (*vreg_reg_fn_t)(struct cpu_user_regs *regs, register_t *r,
+                                   bool read);
 
 static inline bool vreg_emulate_cp32(struct cpu_user_regs *regs, union hsr hsr,
-                                     vreg_reg32_fn_t fn)
+                                     vreg_reg_fn_t fn)
 {
     struct hsr_cp32 cp32 = hsr.cp32;
     /*
@@ -18,7 +18,7 @@ static inline bool vreg_emulate_cp32(struct cpu_user_regs *regs, union hsr hsr,
      * implementation error in the emulation (such as not correctly
      * setting r).
      */
-    uint32_t r = 0;
+    register_t r = 0;
     bool ret;
 
     if ( !cp32.read )
@@ -64,11 +64,11 @@ static inline bool vreg_emulate_cp64(struct cpu_user_regs *regs, union hsr hsr,
 }
 
 #ifdef CONFIG_ARM_64
-static inline bool vreg_emulate_sysreg32(struct cpu_user_regs *regs, union hsr hsr,
-                                         vreg_reg32_fn_t fn)
+static inline bool vreg_emulate_sysreg(struct cpu_user_regs *regs, union hsr hsr,
+                                         vreg_reg_fn_t fn)
 {
     struct hsr_sysreg sysreg = hsr.sysreg;
-    uint32_t r = 0;
+    register_t r = 0;
     bool ret;
 
     if ( !sysreg.read )
@@ -81,30 +81,6 @@ static inline bool vreg_emulate_sysreg32(struct cpu_user_regs *regs, union hsr h
 
     return ret;
 }
-
-static inline bool vreg_emulate_sysreg64(struct cpu_user_regs *regs, union hsr hsr,
-                                         vreg_reg64_fn_t fn)
-{
-    struct hsr_sysreg sysreg = hsr.sysreg;
-    /*
-     * Initialize to zero to avoid leaking data if there is an
-     * implementation error in the emulation (such as not correctly
-     * setting x).
-     */
-    uint64_t x = 0;
-    bool ret;
-
-    if ( !sysreg.read )
-        x = get_user_reg(regs, sysreg.reg);
-
-    ret = fn(regs, &x, sysreg.read);
-
-    if ( ret && sysreg.read )
-        set_user_reg(regs, sysreg.reg, x);
-
-    return ret;
-}
-
 #endif
 
 #define VREG_REG_MASK(size) ((~0UL) >> (BITS_PER_LONG - ((1 << (size)) * 8)))