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authorMarc Zyngier <maz@kernel.org>2019-12-13 13:25:25 +0000
committerMarc Zyngier <maz@kernel.org>2020-01-23 10:38:14 +0000
commit0e20f5e25556c00ee813469d373b00abcf298708 (patch)
tree3503fff95c58e755c203374e037fc445f1c678cf /virt
parent31a9b0b11b1c5264433a4fa1e1e1e8aa03954b1c (diff)
KVM: arm/arm64: Cleanup MMIO handling
Our MMIO handling is a bit odd, in the sense that it uses an intermediate per-vcpu structure to store the various decoded information that describe the access. But the same information is readily available in the HSR/ESR_EL2 field, and we actually use this field to populate the structure. Let's simplify the whole thing by getting rid of the superfluous structure and save a (tiny) bit of space in the vcpu structure. [32bit fix courtesy of Olof Johansson <olof@lixom.net>] Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/arm/mmio.c70
-rw-r--r--virt/kvm/arm/mmu.c1
2 files changed, 22 insertions, 49 deletions
diff --git a/virt/kvm/arm/mmio.c b/virt/kvm/arm/mmio.c
index 1bb71acd53f2..aedfcff99ac5 100644
--- a/virt/kvm/arm/mmio.c
+++ b/virt/kvm/arm/mmio.c
@@ -5,7 +5,6 @@
*/
#include <linux/kvm_host.h>
-#include <asm/kvm_mmio.h>
#include <asm/kvm_emulate.h>
#include <trace/events/kvm.h>
@@ -92,26 +91,23 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
vcpu->mmio_needed = 0;
- if (!run->mmio.is_write) {
- len = run->mmio.len;
- if (len > sizeof(unsigned long))
- return -EINVAL;
-
+ if (!kvm_vcpu_dabt_iswrite(vcpu)) {
+ len = kvm_vcpu_dabt_get_as(vcpu);
data = kvm_mmio_read_buf(run->mmio.data, len);
- if (vcpu->arch.mmio_decode.sign_extend &&
+ if (kvm_vcpu_dabt_issext(vcpu) &&
len < sizeof(unsigned long)) {
mask = 1U << ((len * 8) - 1);
data = (data ^ mask) - mask;
}
- if (!vcpu->arch.mmio_decode.sixty_four)
+ if (!kvm_vcpu_dabt_issf(vcpu))
data = data & 0xffffffff;
trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr,
&data);
data = vcpu_data_host_to_guest(vcpu, data, len);
- vcpu_set_reg(vcpu, vcpu->arch.mmio_decode.rt, data);
+ vcpu_set_reg(vcpu, kvm_vcpu_dabt_get_rd(vcpu), data);
}
/*
@@ -123,36 +119,6 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
return 0;
}
-static int decode_hsr(struct kvm_vcpu *vcpu, bool *is_write, int *len)
-{
- unsigned long rt;
- int access_size;
- bool sign_extend;
- bool sixty_four;
-
- if (kvm_vcpu_dabt_iss1tw(vcpu)) {
- /* page table accesses IO mem: tell guest to fix its TTBR */
- kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
- return 1;
- }
-
- access_size = kvm_vcpu_dabt_get_as(vcpu);
- if (unlikely(access_size < 0))
- return access_size;
-
- *is_write = kvm_vcpu_dabt_iswrite(vcpu);
- sign_extend = kvm_vcpu_dabt_issext(vcpu);
- sixty_four = kvm_vcpu_dabt_issf(vcpu);
- rt = kvm_vcpu_dabt_get_rd(vcpu);
-
- *len = access_size;
- vcpu->arch.mmio_decode.sign_extend = sign_extend;
- vcpu->arch.mmio_decode.rt = rt;
- vcpu->arch.mmio_decode.sixty_four = sixty_four;
-
- return 0;
-}
-
int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
phys_addr_t fault_ipa)
{
@@ -164,15 +130,10 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
u8 data_buf[8];
/*
- * Prepare MMIO operation. First decode the syndrome data we get
- * from the CPU. Then try if some in-kernel emulation feels
- * responsible, otherwise let user space do its magic.
+ * No valid syndrome? Ask userspace for help if it has
+ * voluntered to do so, and bail out otherwise.
*/
- if (kvm_vcpu_dabt_isvalid(vcpu)) {
- ret = decode_hsr(vcpu, &is_write, &len);
- if (ret)
- return ret;
- } else {
+ if (!kvm_vcpu_dabt_isvalid(vcpu)) {
if (vcpu->kvm->arch.return_nisv_io_abort_to_user) {
run->exit_reason = KVM_EXIT_ARM_NISV;
run->arm_nisv.esr_iss = kvm_vcpu_dabt_iss_nisv_sanitized(vcpu);
@@ -184,7 +145,20 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
return -ENOSYS;
}
- rt = vcpu->arch.mmio_decode.rt;
+ /* Page table accesses IO mem: tell guest to fix its TTBR */
+ if (kvm_vcpu_dabt_iss1tw(vcpu)) {
+ kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
+ return 1;
+ }
+
+ /*
+ * Prepare MMIO operation. First decode the syndrome data we get
+ * from the CPU. Then try if some in-kernel emulation feels
+ * responsible, otherwise let user space do its magic.
+ */
+ is_write = kvm_vcpu_dabt_iswrite(vcpu);
+ len = kvm_vcpu_dabt_get_as(vcpu);
+ rt = kvm_vcpu_dabt_get_rd(vcpu);
if (is_write) {
data = vcpu_data_guest_to_host(vcpu, vcpu_get_reg(vcpu, rt),
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index e3ad95013192..a4fa81d75e84 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -14,7 +14,6 @@
#include <asm/cacheflush.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_mmu.h>
-#include <asm/kvm_mmio.h>
#include <asm/kvm_ras.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_emulate.h>