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 --- virt/kvm/arm/arm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'virt') diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index bd5c55916d0d..f149c79fd6ef 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -1332,6 +1332,8 @@ static void cpu_hyp_reset(void) static void cpu_hyp_reinit(void) { + kvm_init_host_cpu_context(&this_cpu_ptr(&kvm_host_data)->host_ctxt); + cpu_hyp_reset(); if (is_kernel_in_hyp_mode()) @@ -1569,7 +1571,6 @@ static int init_hyp_mode(void) kvm_host_data_t *cpu_data; cpu_data = per_cpu_ptr(&kvm_host_data, cpu); - kvm_init_host_cpu_context(&cpu_data->host_ctxt, cpu); err = create_hyp_mappings(cpu_data, cpu_data + 1, PAGE_HYP); if (err) { -- cgit v1.2.3-55-g7522