Commit f8a6c5f3 authored by John Snow's avatar John Snow
Browse files

ahci: explicitly reject bad engine states on post_load 



Currently, we let ahci_cond_start_engines reject weird configurations
where either the DMA (CLB) or FIS engines are said to be started, but
their matching on/off control bit is toggled off.

There should be no way to achieve this, since any time you toggle the
control bit off, the status bit should always follow synchronously.

Preparing for a refactor in cond_start_engines, move the rejection logic
straight up into post_load.

Signed-off-by: default avatarJohn Snow <jsnow@redhat.com>
Message-id: 1454103689-13042-4-git-send-email-jsnow@redhat.com
parent f32a2f33

hw/ide/ahci.c

+13 −8
Original line number Diff line number Diff line
@@ -218,10 +218,6 @@ static int ahci_cond_start_engines(AHCIDevice *ad, bool allow_stop) 
    } else if (pr->cmd & PORT_CMD_LIST_ON) {

        if (allow_stop) {

            ahci_unmap_clb_address(ad);

        } else {

            error_report("AHCI: DMA engine should be off, "

                         "but appears to still be running");

            return -1;

        }

    }
@@ -234,10 +230,6 @@ static int ahci_cond_start_engines(AHCIDevice *ad, bool allow_stop) 
    } else if (pr->cmd & PORT_CMD_FIS_ON) {

        if (allow_stop) {

            ahci_unmap_fis_address(ad);

        } else {

            error_report("AHCI: FIS receive engine should be off, "

                         "but appears to still be running");

            return -1;

        }

    }
@@ -1568,10 +1560,23 @@ static int ahci_state_post_load(void *opaque, int version_id) 
    int i, j;

    struct AHCIDevice *ad;

    NCQTransferState *ncq_tfs;

    AHCIPortRegs *pr;

    AHCIState *s = opaque;



    for (i = 0; i < s->ports; i++) {

        ad = &s->dev[i];

        pr = &ad->port_regs;



        if (!(pr->cmd & PORT_CMD_START) && (pr->cmd & PORT_CMD_LIST_ON)) {

            error_report("AHCI: DMA engine should be off, but status bit "

                         "indicates it is still running.");

            return -1;

        }

        if (!(pr->cmd & PORT_CMD_FIS_RX) && (pr->cmd & PORT_CMD_FIS_ON)) {

            error_report("AHCI: FIS RX engine should be off, but status bit "

                         "indicates it is still running.");

            return -1;

        }



        /* Only remap the CLB address if appropriate, disallowing a state

         * transition from 'on' to 'off' it should be consistent here. */