From 1e0cf16cdad1ba53e9eeee8746fe57de42f20c97 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 5 Jul 2019 23:35:56 +0100 Subject: KVM: arm/arm64: Initialise host's MPIDRs by reading the actual register As part of setting up the host context, we populate its MPIDR by using cpu_logical_map(). It turns out that contrary to arm64, cpu_logical_map() on 32bit ARM doesn't return the *full* MPIDR, but a truncated version. This leaves the host MPIDR slightly corrupted after the first run of a VM, since we won't correctly restore the MPIDR on exit. Oops. Since we cannot trust cpu_logical_map(), let's adopt a different strategy. We move the initialization of the host CPU context as part of the per-CPU initialization (which, in retrospect, makes a lot of sense), and directly read the MPIDR from the HW. This is guaranteed to work on both arm and arm64. Reported-by: Andre Przywara Tested-by: Andre Przywara Fixes: 32f139551954 ("arm/arm64: KVM: Statically configure the host's view of MPIDR") Signed-off-by: Marc Zyngier --- arch/arm/include/asm/kvm_host.h | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index e74e8f408987..8a37c8e89777 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -15,7 +15,6 @@ #include #include #include -#include #include #define __KVM_HAVE_ARCH_INTC_INITIALIZED @@ -147,11 +146,10 @@ struct kvm_host_data { typedef struct kvm_host_data kvm_host_data_t; -static inline void kvm_init_host_cpu_context(struct kvm_cpu_context *cpu_ctxt, - int cpu) +static inline void kvm_init_host_cpu_context(struct kvm_cpu_context *cpu_ctxt) { /* The host's MPIDR is immutable, so let's set it up at boot time */ - cpu_ctxt->cp15[c0_MPIDR] = cpu_logical_map(cpu); + cpu_ctxt->cp15[c0_MPIDR] = read_cpuid_mpidr(); } struct vcpu_reset_state { -- cgit v1.2.3