[PATCH v3 5/8] KVM: arm: vgic: Support 64-bit data manipulation on 32-bit host systems

Vladimir Murzin vladimir.murzin at arm.com
Thu Sep 8 09:06:47 PDT 2016


We have couple of 64-bit registers defined in GICv3 architecture, so
unsigned long accesses to these registers will only access a single
32-bit part of that regitser. On the other hand these registers can't
be accessed as 64-bit with a single instruction like ldrd/strd or
ldmia/stmia if we run a 32-bit host because KVM does not support
access to MMIO space done by these instructions.

It means that a 32-bit guest accesses these registers in 32-bit
chunks, so the only thing we need to do is to ensure that
extract_bytes() always takes 64-bit data.

Since we are here fix couple of other width related issues catched by
gcc

Signed-off-by: Vladimir Murzin <vladimir.murzin at arm.com>
---
 virt/kvm/arm/vgic/vgic-mmio-v3.c |    6 +++---
 virt/kvm/arm/vgic/vgic-mmio.h    |    2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index acbe691..0d3c76a 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -23,7 +23,7 @@
 #include "vgic-mmio.h"
 
 /* extract @num bytes at @offset bytes offset in data */
-unsigned long extract_bytes(unsigned long data, unsigned int offset,
+unsigned long extract_bytes(u64 data, unsigned int offset,
 			    unsigned int num)
 {
 	return (data >> (offset * 8)) & GENMASK_ULL(num * 8 - 1, 0);
@@ -181,7 +181,7 @@ static unsigned long vgic_mmio_read_v3r_typer(struct kvm_vcpu *vcpu,
 	int target_vcpu_id = vcpu->vcpu_id;
 	u64 value;
 
-	value = (mpidr & GENMASK(23, 0)) << 32;
+	value = (u64)(mpidr & GENMASK(23, 0)) << 32;
 	value |= ((target_vcpu_id & 0xffff) << 8);
 	if (target_vcpu_id == atomic_read(&vcpu->kvm->online_vcpus) - 1)
 		value |= GICR_TYPER_LAST;
@@ -611,7 +611,7 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg)
 	bool broadcast;
 
 	sgi = (reg & ICC_SGI1R_SGI_ID_MASK) >> ICC_SGI1R_SGI_ID_SHIFT;
-	broadcast = reg & BIT(ICC_SGI1R_IRQ_ROUTING_MODE_BIT);
+	broadcast = reg & BIT_ULL(ICC_SGI1R_IRQ_ROUTING_MODE_BIT);
 	target_cpus = (reg & ICC_SGI1R_TARGET_LIST_MASK) >> ICC_SGI1R_TARGET_LIST_SHIFT;
 	mpidr = SGI_AFFINITY_LEVEL(reg, 3);
 	mpidr |= SGI_AFFINITY_LEVEL(reg, 2);
diff --git a/virt/kvm/arm/vgic/vgic-mmio.h b/virt/kvm/arm/vgic/vgic-mmio.h
index 0b3ecf9..80f92ce 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.h
+++ b/virt/kvm/arm/vgic/vgic-mmio.h
@@ -96,7 +96,7 @@ unsigned long vgic_data_mmio_bus_to_host(const void *val, unsigned int len);
 void vgic_data_host_to_mmio_bus(void *buf, unsigned int len,
 				unsigned long data);
 
-unsigned long extract_bytes(unsigned long data, unsigned int offset,
+unsigned long extract_bytes(u64 data, unsigned int offset,
 			    unsigned int num);
 
 u64 update_64bit_reg(u64 reg, unsigned int offset, unsigned int len,
-- 
1.7.9.5




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