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authorMarc Zyngier <marc.zyngier@arm.com>2013-02-12 12:40:22 +0000
committerMarc Zyngier <marc.zyngier@arm.com>2013-11-07 19:09:04 +0000
commit6d89d2d9b5bac9dbe40ee106ceda9307b6265234 (patch)
treedc2f8fad0be6afabbbfccca1311be40298449cd2 /arch/arm/kvm
parentd241aac798eb042e605f78c31a4122e583b2cd13 (diff)
arm/arm64: KVM: MMIO support for BE guest
Do the necessary byteswap when host and guest have different views of the universe. Actually, the only case we need to take care of is when the guest is BE. All the other cases are naturally handled. Also be careful about endianness when the data is being memcopy-ed from/to the run buffer. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm/kvm')
-rw-r--r--arch/arm/kvm/mmio.c86
1 files changed, 75 insertions, 11 deletions
diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c
index 0c25d9487d53..4cb5a93182e9 100644
--- a/arch/arm/kvm/mmio.c
+++ b/arch/arm/kvm/mmio.c
@@ -23,6 +23,68 @@
#include "trace.h"
+static void mmio_write_buf(char *buf, unsigned int len, unsigned long data)
+{
+ void *datap = NULL;
+ union {
+ u8 byte;
+ u16 hword;
+ u32 word;
+ u64 dword;
+ } tmp;
+
+ switch (len) {
+ case 1:
+ tmp.byte = data;
+ datap = &tmp.byte;
+ break;
+ case 2:
+ tmp.hword = data;
+ datap = &tmp.hword;
+ break;
+ case 4:
+ tmp.word = data;
+ datap = &tmp.word;
+ break;
+ case 8:
+ tmp.dword = data;
+ datap = &tmp.dword;
+ break;
+ }
+
+ memcpy(buf, datap, len);
+}
+
+static unsigned long mmio_read_buf(char *buf, unsigned int len)
+{
+ unsigned long data = 0;
+ union {
+ u16 hword;
+ u32 word;
+ u64 dword;
+ } tmp;
+
+ switch (len) {
+ case 1:
+ data = buf[0];
+ break;
+ case 2:
+ memcpy(&tmp.hword, buf, len);
+ data = tmp.hword;
+ break;
+ case 4:
+ memcpy(&tmp.word, buf, len);
+ data = tmp.word;
+ break;
+ case 8:
+ memcpy(&tmp.dword, buf, len);
+ data = tmp.dword;
+ break;
+ }
+
+ return data;
+}
+
/**
* kvm_handle_mmio_return -- Handle MMIO loads after user space emulation
* @vcpu: The VCPU pointer
@@ -33,28 +95,27 @@
*/
int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
- unsigned long *dest;
+ unsigned long data;
unsigned int len;
int mask;
if (!run->mmio.is_write) {
- dest = vcpu_reg(vcpu, vcpu->arch.mmio_decode.rt);
- *dest = 0;
-
len = run->mmio.len;
if (len > sizeof(unsigned long))
return -EINVAL;
- memcpy(dest, run->mmio.data, len);
-
- trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr,
- *((u64 *)run->mmio.data));
+ data = mmio_read_buf(run->mmio.data, len);
if (vcpu->arch.mmio_decode.sign_extend &&
len < sizeof(unsigned long)) {
mask = 1U << ((len * 8) - 1);
- *dest = (*dest ^ mask) - mask;
+ data = (data ^ mask) - mask;
}
+
+ trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr,
+ data);
+ data = vcpu_data_host_to_guest(vcpu, data, len);
+ *vcpu_reg(vcpu, vcpu->arch.mmio_decode.rt) = data;
}
return 0;
@@ -105,6 +166,7 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
phys_addr_t fault_ipa)
{
struct kvm_exit_mmio mmio;
+ unsigned long data;
unsigned long rt;
int ret;
@@ -125,13 +187,15 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
}
rt = vcpu->arch.mmio_decode.rt;
+ data = vcpu_data_guest_to_host(vcpu, *vcpu_reg(vcpu, rt), mmio.len);
+
trace_kvm_mmio((mmio.is_write) ? KVM_TRACE_MMIO_WRITE :
KVM_TRACE_MMIO_READ_UNSATISFIED,
mmio.len, fault_ipa,
- (mmio.is_write) ? *vcpu_reg(vcpu, rt) : 0);
+ (mmio.is_write) ? data : 0);
if (mmio.is_write)
- memcpy(mmio.data, vcpu_reg(vcpu, rt), mmio.len);
+ mmio_write_buf(mmio.data, mmio.len, data);
if (vgic_handle_mmio(vcpu, run, &mmio))
return 1;