Re: [PATCH v2 4/4] KVM: arm64: Get rid of old vcpu_reg()

[Marc Zyngier]

On 04/12/15 10:26, Pavel Fedin wrote:
> Using oldstyle vcpu_reg() accessor is proven to be inappropriate and
> unsafe on ARM64. This patch converts the rest of use cases to new
> accessors and completely removes vcpu_reg() on ARM64.
> 
> Signed-off-by: Pavel Fedin 

Reviewed-by: Marc Zyngier 

M.
-- 
Jazz is not dead. It just smells funny...
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[PATCH v2 4/4] KVM: arm64: Get rid of old vcpu_reg()

[Pavel Fedin]

Using oldstyle vcpu_reg() accessor is proven to be inappropriate and
unsafe on ARM64. This patch converts the rest of use cases to new
accessors and completely removes vcpu_reg() on ARM64.

Signed-off-by: Pavel Fedin 
---
 arch/arm/kvm/psci.c  | 20 ++--
 arch/arm64/include/asm/kvm_emulate.h | 11 +++
 arch/arm64/kvm/handle_exit.c |  2 +-
 3 files changed, 14 insertions(+), 19 deletions(-)

diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index 0b55696..a9b3b90 100644
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -75,7 +75,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu 
*source_vcpu)
unsigned long context_id;
phys_addr_t target_pc;
 
-   cpu_id = *vcpu_reg(source_vcpu, 1) & MPIDR_HWID_BITMASK;
+   cpu_id = vcpu_get_reg(source_vcpu, 1) & MPIDR_HWID_BITMASK;
if (vcpu_mode_is_32bit(source_vcpu))
cpu_id &= ~((u32) 0);
 
@@ -94,8 +94,8 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu 
*source_vcpu)
return PSCI_RET_INVALID_PARAMS;
}
 
-   target_pc = *vcpu_reg(source_vcpu, 2);
-   context_id = *vcpu_reg(source_vcpu, 3);
+   target_pc = vcpu_get_reg(source_vcpu, 2);
+   context_id = vcpu_get_reg(source_vcpu, 3);
 
kvm_reset_vcpu(vcpu);
 
@@ -114,7 +114,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu 
*source_vcpu)
 * NOTE: We always update r0 (or x0) because for PSCI v0.1
 * the general puspose registers are undefined upon CPU_ON.
 */
-   *vcpu_reg(vcpu, 0) = context_id;
+   vcpu_set_reg(vcpu, 0, context_id);
vcpu->arch.power_off = false;
smp_mb();   /* Make sure the above is visible */
 
@@ -134,8 +134,8 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct 
kvm_vcpu *vcpu)
struct kvm *kvm = vcpu->kvm;
struct kvm_vcpu *tmp;
 
-   target_affinity = *vcpu_reg(vcpu, 1);
-   lowest_affinity_level = *vcpu_reg(vcpu, 2);
+   target_affinity = vcpu_get_reg(vcpu, 1);
+   lowest_affinity_level = vcpu_get_reg(vcpu, 2);
 
/* Determine target affinity mask */
target_affinity_mask = psci_affinity_mask(lowest_affinity_level);
@@ -209,7 +209,7 @@ int kvm_psci_version(struct kvm_vcpu *vcpu)
 static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
 {
int ret = 1;
-   unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
+   unsigned long psci_fn = vcpu_get_reg(vcpu, 0) & ~((u32) 0);
unsigned long val;
 
switch (psci_fn) {
@@ -273,13 +273,13 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
break;
}
 
-   *vcpu_reg(vcpu, 0) = val;
+   vcpu_set_reg(vcpu, 0, val);
return ret;
 }
 
 static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
 {
-   unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
+   unsigned long psci_fn = vcpu_get_reg(vcpu, 0) & ~((u32) 0);
unsigned long val;
 
switch (psci_fn) {
@@ -295,7 +295,7 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
break;
}
 
-   *vcpu_reg(vcpu, 0) = val;
+   vcpu_set_reg(vcpu, 0, val);
return 1;
 }
 
diff --git a/arch/arm64/include/asm/kvm_emulate.h 
b/arch/arm64/include/asm/kvm_emulate.h
index 5a182af..25a4021 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -100,15 +100,10 @@ static inline void vcpu_set_thumb(struct kvm_vcpu *vcpu)
 }
 
 /*
- * vcpu_reg should always be passed a register number coming from a
- * read of ESR_EL2. Otherwise, it may give the wrong result on AArch32
- * with banked registers.
+ * vcpu_get_reg and vcpu_set_reg should always be passed a register number
+ * coming from a read of ESR_EL2. Otherwise, it may give the wrong result on
+ * AArch32 with banked registers.
  */
-static inline unsigned long *vcpu_reg(const struct kvm_vcpu *vcpu, u8 reg_num)
-{
-   return (unsigned long *)_gp_regs(vcpu)->regs.regs[reg_num];
-}
-
 static inline unsigned long vcpu_get_reg(const struct kvm_vcpu *vcpu,
 u8 reg_num)
 {
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 68a0759..15f0477 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -37,7 +37,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run 
*run)
 {
int ret;
 
-   trace_kvm_hvc_arm64(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
+   trace_kvm_hvc_arm64(*vcpu_pc(vcpu), vcpu_get_reg(vcpu, 0),
kvm_vcpu_hvc_get_imm(vcpu));
 
ret = kvm_psci_call(vcpu);
-- 
2.4.4

--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html