On Mon, 13 May 2019 at 13:46, Dongjiu Geng <gengdongjiu@xxxxxxxxxx> wrote:
>
> Add SIGBUS signal handler. In this handler, it checks the SIGBUS type,
> translates the host VA delivered by host to guest PA, then fill this PA
> to guest APEI GHES memory, then notify guest according to the SIGBUS type.
>
> If guest accesses the poisoned memory, it generates Synchronous External
> Abort(SEA). Then host kernel gets an APEI notification and call memory_failure()
> to unmapped the affected page for the guest's stage 2, finally return
> to guest.
>
> Guest continues to access PG_hwpoison page, it will trap to KVM as stage2 fault,
> then a SIGBUS_MCEERR_AR synchronous signal is delivered to Qemu, Qemu record this
> error address into guest APEI GHES memory and notify guest using
> Synchronous-External-Abort(SEA).
>
> Suggested-by: James Morse <james.morse@xxxxxxx>
> Signed-off-by: Dongjiu Geng <gengdongjiu@xxxxxxxxxx>
> +void kvm_arch_on_sigbus_vcpu(CPUState *c, int code, void *addr)
> +{
> + ARMCPU *cpu = ARM_CPU(c);
> + CPUARMState *env = &cpu->env;
> + ram_addr_t ram_addr;
> + hwaddr paddr;
> +
> + assert(code == BUS_MCEERR_AR || code == BUS_MCEERR_AO);
> +
> + if (addr) {
> + ram_addr = qemu_ram_addr_from_host(addr);
> + if (ram_addr != RAM_ADDR_INVALID &&
> + kvm_physical_memory_addr_from_host(c->kvm_state, addr, &paddr)) {
> + kvm_hwpoison_page_add(ram_addr);
> + /* Asynchronous signal will be masked by main thread, so
> + * only handle synchronous signal.
> + */
> + if (code == BUS_MCEERR_AR) {
> + kvm_cpu_synchronize_state(c);
> + if (GHES_CPER_FAIL != ghes_record_errors(ACPI_HEST_NOTIFY_SEA, paddr)) {
> + kvm_inject_arm_sea(c);
> + } else {
> + fprintf(stderr, "failed to record the error\n");
> + }
> + }
> + return;
> + }
> + fprintf(stderr, "Hardware memory error for memory used by "
> + "QEMU itself instead of guest system!\n");
> + }
> +
> + if (code == BUS_MCEERR_AR) {
> + fprintf(stderr, "Hardware memory error!\n");
> + exit(1);
> + }
> +}
This code appears to still be unconditionally trying to
notify the guest of the error via the ACPI tables without
checking whether those ACPI tables even exist. I told you
about this in a previous round of review :-(
thanks
-- PMM
