KVM: arm64: Initialise hypervisor copies of host symbols unconditionally

[ Upstream commit 6c165223e9a6384aa1e934b90f2650e71adb972a ]

The nVHE object at EL2 maintains its own copies of some host variables
so that, when pKVM is enabled, the host cannot directly modify the
hypervisor state. When running in normal nVHE mode, however, these
variables are still mirrored at EL2 but are not initialised.

Initialise the hypervisor symbols from the host copies regardless of
pKVM, ensuring that any reference to this data at EL2 with normal nVHE
will return a sensibly initialised value.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-16-will@kernel.org
Stable-dep-of: e81625218bf7 ("KVM: arm64: Advertise ID_AA64PFR0_EL1.CSV2/3 to protected VMs")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 94d33e296e10c57c34008af96d7a9adcb72d99ef..e40606a560997a67ddf3a013b22c156fa2bd47e0 100644 (file)
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1870,11 +1870,8 @@ static int do_pkvm_init(u32 hyp_va_bits)
        return ret;
 }
 
-static int kvm_hyp_init_protection(u32 hyp_va_bits)
+static void kvm_hyp_init_symbols(void)
 {
-       void *addr = phys_to_virt(hyp_mem_base);
-       int ret;
-
        kvm_nvhe_sym(id_aa64pfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
        kvm_nvhe_sym(id_aa64pfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1);
        kvm_nvhe_sym(id_aa64isar0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR0_EL1);
@@ -1883,6 +1880,12 @@ static int kvm_hyp_init_protection(u32 hyp_va_bits)
        kvm_nvhe_sym(id_aa64mmfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
        kvm_nvhe_sym(id_aa64mmfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
        kvm_nvhe_sym(id_aa64mmfr2_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR2_EL1);
+}
+
+static int kvm_hyp_init_protection(u32 hyp_va_bits)
+{
+       void *addr = phys_to_virt(hyp_mem_base);
+       int ret;
 
        ret = create_hyp_mappings(addr, addr + hyp_mem_size, PAGE_HYP);
        if (ret)
@@ -2057,6 +2060,8 @@ static int init_hyp_mode(void)
                cpu_prepare_hyp_mode(cpu);
        }
 
+       kvm_hyp_init_symbols();
+
        if (is_protected_kvm_enabled()) {
                init_cpu_logical_map();
 
@@ -2064,9 +2069,7 @@ static int init_hyp_mode(void)
                        err = -ENODEV;
                        goto out_err;
                }
-       }
 
-       if (is_protected_kvm_enabled()) {
                err = kvm_hyp_init_protection(hyp_va_bits);
                if (err) {
                        kvm_err("Failed to init hyp memory protection\n");