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-rw-r--r--arch/arm64/kvm/hyp/entry.S52
-rw-r--r--arch/arm64/kvm/hyp/switch.c20
-rw-r--r--arch/arm64/kvm/hyp/sysreg-sr.c4
-rw-r--r--arch/arm64/kvm/hyp/tlb.c12
4 files changed, 49 insertions, 39 deletions
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S
index e5cc8d66bf53..d22d0534dd60 100644
--- a/arch/arm64/kvm/hyp/entry.S
+++ b/arch/arm64/kvm/hyp/entry.S
@@ -22,7 +22,12 @@
.text
.pushsection .hyp.text, "ax"
+/*
+ * We treat x18 as callee-saved as the host may use it as a platform
+ * register (e.g. for shadow call stack).
+ */
.macro save_callee_saved_regs ctxt
+ str x18, [\ctxt, #CPU_XREG_OFFSET(18)]
stp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
stp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
stp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
@@ -32,6 +37,8 @@
.endm
.macro restore_callee_saved_regs ctxt
+ // We require \ctxt is not x18-x28
+ ldr x18, [\ctxt, #CPU_XREG_OFFSET(18)]
ldp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
ldp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
ldp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
@@ -44,11 +51,11 @@
* u64 __guest_enter(struct kvm_vcpu *vcpu,
* struct kvm_cpu_context *host_ctxt);
*/
-ENTRY(__guest_enter)
+SYM_FUNC_START(__guest_enter)
// x0: vcpu
// x1: host context
// x2-x17: clobbered by macros
- // x18: guest context
+ // x29: guest context
// Store the host regs
save_callee_saved_regs x1
@@ -67,38 +74,34 @@ alternative_else_nop_endif
ret
1:
- add x18, x0, #VCPU_CONTEXT
+ add x29, x0, #VCPU_CONTEXT
// Macro ptrauth_switch_to_guest format:
// ptrauth_switch_to_guest(guest cxt, tmp1, tmp2, tmp3)
// The below macro to restore guest keys is not implemented in C code
// as it may cause Pointer Authentication key signing mismatch errors
// when this feature is enabled for kernel code.
- ptrauth_switch_to_guest x18, x0, x1, x2
+ ptrauth_switch_to_guest x29, x0, x1, x2
// Restore guest regs x0-x17
- ldp x0, x1, [x18, #CPU_XREG_OFFSET(0)]
- ldp x2, x3, [x18, #CPU_XREG_OFFSET(2)]
- ldp x4, x5, [x18, #CPU_XREG_OFFSET(4)]
- ldp x6, x7, [x18, #CPU_XREG_OFFSET(6)]
- ldp x8, x9, [x18, #CPU_XREG_OFFSET(8)]
- ldp x10, x11, [x18, #CPU_XREG_OFFSET(10)]
- ldp x12, x13, [x18, #CPU_XREG_OFFSET(12)]
- ldp x14, x15, [x18, #CPU_XREG_OFFSET(14)]
- ldp x16, x17, [x18, #CPU_XREG_OFFSET(16)]
-
- // Restore guest regs x19-x29, lr
- restore_callee_saved_regs x18
-
- // Restore guest reg x18
- ldr x18, [x18, #CPU_XREG_OFFSET(18)]
+ ldp x0, x1, [x29, #CPU_XREG_OFFSET(0)]
+ ldp x2, x3, [x29, #CPU_XREG_OFFSET(2)]
+ ldp x4, x5, [x29, #CPU_XREG_OFFSET(4)]
+ ldp x6, x7, [x29, #CPU_XREG_OFFSET(6)]
+ ldp x8, x9, [x29, #CPU_XREG_OFFSET(8)]
+ ldp x10, x11, [x29, #CPU_XREG_OFFSET(10)]
+ ldp x12, x13, [x29, #CPU_XREG_OFFSET(12)]
+ ldp x14, x15, [x29, #CPU_XREG_OFFSET(14)]
+ ldp x16, x17, [x29, #CPU_XREG_OFFSET(16)]
+
+ // Restore guest regs x18-x29, lr
+ restore_callee_saved_regs x29
// Do not touch any register after this!
eret
sb
-ENDPROC(__guest_enter)
-ENTRY(__guest_exit)
+SYM_INNER_LABEL(__guest_exit, SYM_L_GLOBAL)
// x0: return code
// x1: vcpu
// x2-x29,lr: vcpu regs
@@ -114,7 +117,7 @@ ENTRY(__guest_exit)
// Retrieve the guest regs x0-x1 from the stack
ldp x2, x3, [sp], #16 // x0, x1
- // Store the guest regs x0-x1 and x4-x18
+ // Store the guest regs x0-x1 and x4-x17
stp x2, x3, [x1, #CPU_XREG_OFFSET(0)]
stp x4, x5, [x1, #CPU_XREG_OFFSET(4)]
stp x6, x7, [x1, #CPU_XREG_OFFSET(6)]
@@ -123,9 +126,8 @@ ENTRY(__guest_exit)
stp x12, x13, [x1, #CPU_XREG_OFFSET(12)]
stp x14, x15, [x1, #CPU_XREG_OFFSET(14)]
stp x16, x17, [x1, #CPU_XREG_OFFSET(16)]
- str x18, [x1, #CPU_XREG_OFFSET(18)]
- // Store the guest regs x19-x29, lr
+ // Store the guest regs x18-x29, lr
save_callee_saved_regs x1
get_host_ctxt x2, x3
@@ -192,4 +194,4 @@ abort_guest_exit_end:
msr spsr_el2, x4
orr x0, x0, x5
1: ret
-ENDPROC(__guest_exit)
+SYM_FUNC_END(__guest_enter)
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 72fbbd86eb5e..dfe8dd172512 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -28,7 +28,15 @@
/* Check whether the FP regs were dirtied while in the host-side run loop: */
static bool __hyp_text update_fp_enabled(struct kvm_vcpu *vcpu)
{
- if (vcpu->arch.host_thread_info->flags & _TIF_FOREIGN_FPSTATE)
+ /*
+ * When the system doesn't support FP/SIMD, we cannot rely on
+ * the _TIF_FOREIGN_FPSTATE flag. However, we always inject an
+ * abort on the very first access to FP and thus we should never
+ * see KVM_ARM64_FP_ENABLED. For added safety, make sure we always
+ * trap the accesses.
+ */
+ if (!system_supports_fpsimd() ||
+ vcpu->arch.host_thread_info->flags & _TIF_FOREIGN_FPSTATE)
vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED |
KVM_ARM64_FP_HOST);
@@ -119,7 +127,7 @@ static void __hyp_text __activate_traps_nvhe(struct kvm_vcpu *vcpu)
write_sysreg(val, cptr_el2);
- if (cpus_have_const_cap(ARM64_WORKAROUND_1319367)) {
+ if (cpus_have_const_cap(ARM64_WORKAROUND_SPECULATIVE_AT_NVHE)) {
struct kvm_cpu_context *ctxt = &vcpu->arch.ctxt;
isb();
@@ -158,11 +166,11 @@ static void deactivate_traps_vhe(void)
write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
/*
- * ARM erratum 1165522 requires the actual execution of the above
- * before we can switch to the EL2/EL0 translation regime used by
+ * ARM errata 1165522 and 1530923 require the actual execution of the
+ * above before we can switch to the EL2/EL0 translation regime used by
* the host.
*/
- asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_1165522));
+ asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_SPECULATIVE_AT_VHE));
write_sysreg(CPACR_EL1_DEFAULT, cpacr_el1);
write_sysreg(vectors, vbar_el1);
@@ -173,7 +181,7 @@ static void __hyp_text __deactivate_traps_nvhe(void)
{
u64 mdcr_el2 = read_sysreg(mdcr_el2);
- if (cpus_have_const_cap(ARM64_WORKAROUND_1319367)) {
+ if (cpus_have_const_cap(ARM64_WORKAROUND_SPECULATIVE_AT_NVHE)) {
u64 val;
/*
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index 22b8128d19f6..7672a978926c 100644
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c
@@ -118,7 +118,7 @@ static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
write_sysreg(ctxt->sys_regs[MPIDR_EL1], vmpidr_el2);
write_sysreg(ctxt->sys_regs[CSSELR_EL1], csselr_el1);
- if (!cpus_have_const_cap(ARM64_WORKAROUND_1319367)) {
+ if (!cpus_have_const_cap(ARM64_WORKAROUND_SPECULATIVE_AT_NVHE)) {
write_sysreg_el1(ctxt->sys_regs[SCTLR_EL1], SYS_SCTLR);
write_sysreg_el1(ctxt->sys_regs[TCR_EL1], SYS_TCR);
} else if (!ctxt->__hyp_running_vcpu) {
@@ -149,7 +149,7 @@ static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
write_sysreg(ctxt->sys_regs[PAR_EL1], par_el1);
write_sysreg(ctxt->sys_regs[TPIDR_EL1], tpidr_el1);
- if (cpus_have_const_cap(ARM64_WORKAROUND_1319367) &&
+ if (cpus_have_const_cap(ARM64_WORKAROUND_SPECULATIVE_AT_NVHE) &&
ctxt->__hyp_running_vcpu) {
/*
* Must only be done for host registers, hence the context
diff --git a/arch/arm64/kvm/hyp/tlb.c b/arch/arm64/kvm/hyp/tlb.c
index c2bc17ca6430..92f560e3e1aa 100644
--- a/arch/arm64/kvm/hyp/tlb.c
+++ b/arch/arm64/kvm/hyp/tlb.c
@@ -23,10 +23,10 @@ static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm,
local_irq_save(cxt->flags);
- if (cpus_have_const_cap(ARM64_WORKAROUND_1165522)) {
+ if (cpus_have_const_cap(ARM64_WORKAROUND_SPECULATIVE_AT_VHE)) {
/*
- * For CPUs that are affected by ARM erratum 1165522, we
- * cannot trust stage-1 to be in a correct state at that
+ * For CPUs that are affected by ARM errata 1165522 or 1530923,
+ * we cannot trust stage-1 to be in a correct state at that
* point. Since we do not want to force a full load of the
* vcpu state, we prevent the EL1 page-table walker to
* allocate new TLBs. This is done by setting the EPD bits
@@ -63,7 +63,7 @@ static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm,
static void __hyp_text __tlb_switch_to_guest_nvhe(struct kvm *kvm,
struct tlb_inv_context *cxt)
{
- if (cpus_have_const_cap(ARM64_WORKAROUND_1319367)) {
+ if (cpus_have_const_cap(ARM64_WORKAROUND_SPECULATIVE_AT_NVHE)) {
u64 val;
/*
@@ -103,7 +103,7 @@ static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm,
write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
isb();
- if (cpus_have_const_cap(ARM64_WORKAROUND_1165522)) {
+ if (cpus_have_const_cap(ARM64_WORKAROUND_SPECULATIVE_AT_VHE)) {
/* Restore the registers to what they were */
write_sysreg_el1(cxt->tcr, SYS_TCR);
write_sysreg_el1(cxt->sctlr, SYS_SCTLR);
@@ -117,7 +117,7 @@ static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm,
{
write_sysreg(0, vttbr_el2);
- if (cpus_have_const_cap(ARM64_WORKAROUND_1319367)) {
+ if (cpus_have_const_cap(ARM64_WORKAROUND_SPECULATIVE_AT_NVHE)) {
/* Ensure write of the host VMID */
isb();
/* Restore the host's TCR_EL1 */
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.