On Thu, 2024-06-27 at 14:48 +0200, Stefano Garzarella wrote:
> On Fri, Jun 21, 2024 at 03:29:09PM GMT, Roy Hopkins wrote:
> > The class function and implementations for updating launch data return
> > a code in case of error. In some cases an error message is generated and
> > in other cases, just the error return value is used.
> >
> > This small refactor adds an 'Error **errp' parameter to all functions
> > which consistently set an error condition if a non-zero value is
> > returned.
> >
> > Signed-off-by: Roy Hopkins <roy.hopk...@suse.com>
> > ---
> > target/i386/sev.c | 67 +++++++++++++++++++++++++----------------------
> > 1 file changed, 35 insertions(+), 32 deletions(-)
> >
> > diff --git a/target/i386/sev.c b/target/i386/sev.c
> > index 30b83f1d77..1900c3d9b4 100644
> > --- a/target/i386/sev.c
> > +++ b/target/i386/sev.c
> > @@ -121,7 +121,8 @@ struct SevCommonStateClass {
> > Error **errp);
> > int (*launch_start)(SevCommonState *sev_common);
> > void (*launch_finish)(SevCommonState *sev_common);
> > - int (*launch_update_data)(SevCommonState *sev_common, hwaddr gpa,
> > uint8_t *ptr, uint64_t len);
> > + int (*launch_update_data)(SevCommonState *sev_common, hwaddr gpa,
> > + uint8_t *ptr, uint64_t len, Error **errp);
> > int (*kvm_init)(ConfidentialGuestSupport *cgs, Error **errp);
> > };
> >
> > @@ -942,14 +943,17 @@ out:
> > return ret;
> > }
> >
> > -static int
> > -sev_launch_update_data(SevCommonState *sev_common, hwaddr gpa, uint8_t
> > *addr, uint64_t len)
> > +static int sev_launch_update_data(SevCommonState *sev_common, hwaddr gpa,
> > + uint8_t *addr, uint64_t len, Error
> > **errp)
> > {
> > int ret, fw_error;
> > struct kvm_sev_launch_update_data update;
> >
> > if (!addr || !len) {
> > - return 1;
>
> Why were we returning 1 before? Was that a mistake?
> Maybe we should mention it in the patch or fix it in another patch.
>
> > + error_setg(errp,
> > + "%s: Invalid parameters provided for updating
> > launch data.",
> > + __func__);
> > + return -1;
> > }
> >
> > update.uaddr = (uintptr_t)addr;
> > @@ -958,8 +962,8 @@ sev_launch_update_data(SevCommonState *sev_common,
> > hwaddr gpa, uint8_t *addr, ui
> > ret = sev_ioctl(sev_common->sev_fd, KVM_SEV_LAUNCH_UPDATE_DATA,
> > &update, &fw_error);
> > if (ret) {
> > - error_report("%s: LAUNCH_UPDATE ret=%d fw_error=%d '%s'",
> > - __func__, ret, fw_error, fw_error_to_str(fw_error));
> > + error_setg(errp, "%s: LAUNCH_UPDATE ret=%d fw_error=%d '%s'",
> > __func__,
> > + ret, fw_error, fw_error_to_str(fw_error));
> > }
> >
> > return ret;
> > @@ -1087,9 +1091,8 @@ sev_launch_finish(SevCommonState *sev_common)
> > migrate_add_blocker(&sev_mig_blocker, &error_fatal);
> > }
> >
> > -static int
> > -snp_launch_update_data(uint64_t gpa, void *hva,
> > - uint32_t len, int type)
> > +static int snp_launch_update_data(uint64_t gpa, void *hva, uint32_t len,
> > + int type, Error **errp)
> > {
> > SevLaunchUpdateData *data;
> >
> > @@ -1104,13 +1107,12 @@ snp_launch_update_data(uint64_t gpa, void *hva,
> > return 0;
> > }
> >
> > -static int
> > -sev_snp_launch_update_data(SevCommonState *sev_common, hwaddr gpa,
> > - uint8_t *ptr, uint64_t len)
> > +static int sev_snp_launch_update_data(SevCommonState *sev_common, hwaddr
> > gpa,
> > + uint8_t *ptr, uint64_t len, Error
> > **errp)
> > {
> > - int ret = snp_launch_update_data(gpa, ptr, len,
> > - KVM_SEV_SNP_PAGE_TYPE_NORMAL);
> > - return ret;
> > + int ret = snp_launch_update_data(gpa, ptr, len,
> > + KVM_SEV_SNP_PAGE_TYPE_NORMAL, errp);
> > + return ret;
>
> Pre-existing, but while we're at it maybe we can remove ret.
>
> > }
> >
> > static int
> > @@ -1162,8 +1164,8 @@ sev_snp_cpuid_info_fill(SnpCpuidInfo *snp_cpuid_info,
> > return 0;
> > }
> >
> > -static int
> > -snp_launch_update_cpuid(uint32_t cpuid_addr, void *hva, uint32_t cpuid_len)
> > +static int snp_launch_update_cpuid(uint32_t cpuid_addr, void *hva,
> > + uint32_t cpuid_len, Error **errp)
> > {
> > KvmCpuidInfo kvm_cpuid_info = {0};
> > SnpCpuidInfo snp_cpuid_info;
> > @@ -1180,26 +1182,26 @@ snp_launch_update_cpuid(uint32_t cpuid_addr, void
> > *hva, uint32_t cpuid_len)
> > } while (ret == -E2BIG);
> >
> > if (ret) {
> > - error_report("SEV-SNP: unable to query CPUID values for CPU: '%s'",
> > - strerror(-ret));
> > - return 1;
> > + error_setg(errp, "SEV-SNP: unable to query CPUID values for CPU:
> > '%s'",
> > + strerror(-ret));
> > + return -1;
> > }
> >
> > ret = sev_snp_cpuid_info_fill(&snp_cpuid_info, &kvm_cpuid_info);
> > if (ret) {
> > - error_report("SEV-SNP: failed to generate CPUID table
> > information");
> > - return 1;
> > + error_setg(errp, "SEV-SNP: failed to generate CPUID table
> > information");
> > + return -1;
>
> Ditto for the 2 changes, although IIUC we never check the return value
> of snp_launch_update_cpuid().
The error returns were changed to -1 for consistency, but on reflection, without
changing every return in this file it had the reverse effect. I'll revert these
back to the original return values.
I did however spot a pre-existing bug when reverting this though.
sev_encrypt_firmware() only considers a negative result from launch_update() as
an error, but the function returns 1 on some errors. I've added a new patch in
v4 that fixes this error.
>
> > }
> >
> > memcpy(hva, &snp_cpuid_info, sizeof(snp_cpuid_info));
> >
> > return snp_launch_update_data(cpuid_addr, hva, cpuid_len,
> > - KVM_SEV_SNP_PAGE_TYPE_CPUID);
> > + KVM_SEV_SNP_PAGE_TYPE_CPUID, errp);
> > }
> >
> > -static int
> > -snp_launch_update_kernel_hashes(SevSnpGuestState *sev_snp, uint32_t addr,
> > - void *hva, uint32_t len)
> > +static int snp_launch_update_kernel_hashes(SevSnpGuestState *sev_snp,
> > + uint32_t addr, void *hva,
> > + uint32_t len, Error **errp)
> > {
> > int type = KVM_SEV_SNP_PAGE_TYPE_ZERO;
> > if (sev_snp->parent_obj.kernel_hashes) {
> > @@ -1211,7 +1213,7 @@ snp_launch_update_kernel_hashes(SevSnpGuestState
> > *sev_snp, uint32_t addr,
> > sizeof(*sev_snp->kernel_hashes_data));
> > type = KVM_SEV_SNP_PAGE_TYPE_NORMAL;
> > }
> > - return snp_launch_update_data(addr, hva, len, type);
> > + return snp_launch_update_data(addr, hva, len, type, errp);
> > }
> >
> > static int
> > @@ -1249,12 +1251,14 @@ snp_populate_metadata_pages(SevSnpGuestState
> > *sev_snp,
> > }
> >
> > if (type == KVM_SEV_SNP_PAGE_TYPE_CPUID) {
> > - ret = snp_launch_update_cpuid(desc->base, hva, desc->len);
> > + ret = snp_launch_update_cpuid(desc->base, hva, desc->len,
> > + &error_fatal);
> > } else if (desc->type == SEV_DESC_TYPE_SNP_KERNEL_HASHES) {
> > ret = snp_launch_update_kernel_hashes(sev_snp, desc->base, hva,
> > - desc->len);
> > + desc->len, &error_fatal);
> > } else {
> > - ret = snp_launch_update_data(desc->base, hva, desc->len, type);
> > + ret = snp_launch_update_data(desc->base, hva, desc->len, type,
> > + &error_fatal);
> > }
> >
> > if (ret) {
> > @@ -1541,9 +1545,8 @@ sev_encrypt_flash(hwaddr gpa, uint8_t *ptr, uint64_t
> > len, Error **errp)
> > if (sev_check_state(sev_common, SEV_STATE_LAUNCH_UPDATE)) {
> > int ret;
> >
> > - ret = klass->launch_update_data(sev_common, gpa, ptr, len);
> > + ret = klass->launch_update_data(sev_common, gpa, ptr, len, errp);
> > if (ret < 0) {
> > - error_setg(errp, "SEV: Failed to encrypt pflash rom");
> > return ret;
> > }
> > }
> > --
> > 2.43.0
> >
>
