diff mbox series

[v4,15/25] KVM: arm64: Initialise hypervisor copies of host symbols unconditionally

Message ID 20221017115209.2099-16-will@kernel.org (mailing list archive)
State New, archived
Headers show
Series KVM: arm64: Introduce pKVM hyp VM and vCPU state at EL2 | expand

Commit Message

Will Deacon Oct. 17, 2022, 11:51 a.m. UTC 
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.

Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
 arch/arm64/kvm/arm.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

Comments

Philippe Mathieu-Daudé Oct. 17, 2022, 8:26 p.m. UTC | #1 
On 17/10/22 13:51, Will Deacon wrote:
> 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.
> 
> Tested-by: Vincent Donnefort <vdonnefort@google.com>
> Signed-off-by: Will Deacon <will@kernel.org>
> ---
>   arch/arm64/kvm/arm.c | 15 +++++++++------
>   1 file changed, 9 insertions(+), 6 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
diff mbox series

Patch

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 30d6fc5d3a93..584626e11797 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1884,11 +1884,8 @@  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);
@@ -1897,6 +1894,12 @@  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)
@@ -2071,6 +2074,8 @@  static int init_hyp_mode(void)
 		cpu_prepare_hyp_mode(cpu);
 	}
 
+	kvm_hyp_init_symbols();
+
 	if (is_protected_kvm_enabled()) {
 		init_cpu_logical_map();
 
@@ -2078,9 +2083,7 @@  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");