On Thu, Jun 12, 2014 at 09:30:13AM -0700, Victor Kamensky wrote:
Fix issue with 32bit guests running on top of BE KVM host. Indexes of high and low words of 64bit cp15 register are swapped in case of big endian code, since 64bit cp15 state is restored or saved with double word write or read instruction.
Define helper macros to access high low words of 64bit cp15 register.
Signed-off-by: Victor Kamensky victor.kamensky@linaro.org
arch/arm64/include/asm/kvm_host.h | 8 ++++++++ arch/arm64/kvm/sys_regs.c | 4 ++-- 2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 0a1d697..e9d2e11 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -140,6 +140,14 @@ struct kvm_vcpu_arch { #define vcpu_sys_reg(v,r) ((v)->arch.ctxt.sys_regs[(r)]) #define vcpu_cp15(v,r) ((v)->arch.ctxt.cp15[(r)]) +#ifdef CONFIG_CPU_BIG_ENDIAN +#define vcpu_cp15_64_high(v,r) ((v)->arch.ctxt.cp15[((r) + 0)]) +#define vcpu_cp15_64_low(v,r) ((v)->arch.ctxt.cp15[((r) + 1)]) +#else +#define vcpu_cp15_64_high(v,r) ((v)->arch.ctxt.cp15[((r) + 1)]) +#define vcpu_cp15_64_low(v,r) ((v)->arch.ctxt.cp15[((r) + 0)]) +#endif
struct kvm_vm_stat { u32 remote_tlb_flush; }; diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 8e65e31..71aa9b0 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -137,9 +137,9 @@ static bool access_vm_reg(struct kvm_vcpu *vcpu, if (!p->is_aarch32) { vcpu_sys_reg(vcpu, r->reg) = val; } else {
vcpu_cp15(vcpu, r->reg) = val & 0xffffffffUL;
vcpu_cp15_64_low(vcpu, r->reg) = val & 0xffffffffUL;
vcpu_cp15(vcpu, r->reg + 1) = val >> 32;
vcpu_cp15_64_high(vcpu, r->reg) = val >> 32;}
1.8.1.4
I thought there was a consensus here about handling 64-bit accesses through the 64-bit values with the vcpu_sys_reg() interface? Did you give up on this for a particular reason?
-Christoffer